Just curious where everyone gets their supplies?
I always tend to make things - at least when it is the worth - using components that make it replicable in future, so I am not so used to use garage sales. Anyway here it is not posible to do it anyway as there are not garage sales nor this tradition in both Spain and Italy (in the Netherlands instead yes but I no longer stay there).
Small mechanical components and gears, pulleys, bearings etc. on Amazon (es, not com that has a wider range of products). With the wide diffusion of the home 3D printers these components as well as the replacement parts for 3D printers (nozzles, heat beds, etc.) are easy to find. As it is not always easy to be sure I made the right choice there is the advantage that I can take the stuff in 1-3 days, see if it is ok and if not have it replaced or refunded for free; as far as I know Amazon is the only online distributor that offer this kind of service. with 19Euro per year I have zero shipment costs in both directions and refund is immediate. I find this great
I also buy on Amazon any kind of small screws, washers, nuts etc. There are good kits between 100 and 500 pieces for a very low price with a range of lengths and sizes that here are very difficult to find; local hardware stores smaller screws are M4 size 
that are almost the bigger I will use.
I explored several places to buy good plastic for laser cutting and until now the better provider for 3mm (any colour and size) is Kitronic. I also buy from Kitronic soldering wires. They sell 100 m coil for a very reasonable price.
For 3D printer filament I bought until now from Geeetech; they sell good material at a very good price (1Kg PLA 1.75 mm 15$) but I should contract with my local custom office to rebate the taxes when I import many rolls of filament. Amazon is a good alternative but I should try before some different provider to find the better balance between price and quality.
For components, I usually buy from three different providers; primarily Farnell.es (when it is available, but they tend to sell only high priced versions of some ones). When I can't find I will use RS-Online that has a very good shipping service in Spain (same day via SEUR of next day). Some stuff I buy from Pimoroni, not rarely custom stuff that then I replicate making some update to the base. The advantage of Pimoroni is that at the date it is the only distributor that also sell in Europe at a decent price some Adafruit and Sparkfun components. In past I bought from Sparkfun online from the US but they sent me the stuff after 6 weeks that is not a reasonable time to wait for a project completion.
What about discrete components like resistors, capacitors, diodes, push buttons, pin arrays etc? In 2014 I developed an almost complex project for a Taiwan clients (but the original commitment was from PayPal) e was based in California and most of the project has been done at home. Then I moved there for a couple of months to complete it. While I was developing this suf I sent him the BOM for the prototypes development; it included the most used resistors, capacitors, diodes, dip switches, pin arrays and also dual side copper plate for PCB milling). They told me that from Taiwan it was not possible to ship so few pieces for them and asked me to complete the list with all the components I was expecting to use. I included also AVR 328P, shif t registers, optoisolators and many more). And they sent me about 70 Kg in a box with 1000 (one thousand !!!) of every piece. I suppose that I don't need to buy this for the next few years ...
Until now, for a lot of practice reasons I use Eurocircuits for PCB prototyping and small production. It is true that they have not super low pricing like China, but the service is exceptional and if you consider the "PCB at 5$" from China, ask for a real cost analysis for example for an Arduino shield, add the shipment time (7-10 days after they build), add the custom taxes price of Eurocircuits is truly competitive.
Enrico
I always tend to make things - at least when it is the worth - using components that make it replicable in future, so I am not so used to use garage sales. Anyway here it is not posible to do it anyway as there are not garage sales nor this tradition in both Spain and Italy (in the Netherlands instead yes but I no longer stay there).
Small mechanical components and gears, pulleys, bearings etc. on Amazon (es, not com that has a wider range of products). With the wide diffusion of the home 3D printers these components as well as the replacement parts for 3D printers (nozzles, heat beds, etc.) are easy to find. As it is not always easy to be sure I made the right choice there is the advantage that I can take the stuff in 1-3 days, see if it is ok and if not have it replaced or refunded for free; as far as I know Amazon is the only online distributor that offer this kind of service. with 19Euro per year I have zero shipment costs in both directions and refund is immediate. I find this great
I also buy on Amazon any kind of small screws, washers, nuts etc. There are good kits between 100 and 500 pieces for a very low price with a range of lengths and sizes that here are very difficult to find; local hardware stores smaller screws are M4 size that are almost the bigger I will use.
I explored several places to buy good plastic for laser cutting and until now the better provider for 3mm (any colour and size) is Kitronic. I also buy from Kitronic soldering wires. They sell 100 m coil for a very reasonable price.
For 3D printer filament I bought until now from Geeetech; they sell good material at a very good price (1Kg PLA 1.75 mm 15$) but I should contract with my local custom office to rebate the taxes when I import many rolls of filament. Amazon is a good alternative but I should try before some different provider to find the better balance between price and quality.
For components, I usually buy from three different providers; primarily Farnell.es (when it is available, but they tend to sell only high priced versions of some ones). When I can't find I will use RS-Online that has a very good shipping service in Spain (same day via SEUR of next day). Some stuff I buy from Pimoroni, not rarely custom stuff that then I replicate making some update to the base. The advantage of Pimoroni is that at the date it is the only distributor that also sell in Europe at a decent price some Adafruit and Sparkfun components. In past I bought from Sparkfun online from the US but they sent me the stuff after 6 weeks that is not a reasonable time to wait for a project completion.
What about discrete components like resistors, capacitors, diodes, push buttons, pin arrays etc? In 2014 I developed an almost complex project for a Taiwan clients (but the original commitment was from PayPal) e was based in California and most of the project has been done at home. Then I moved there for a couple of months to complete it. While I was developing this suf I sent him the BOM for the prototypes development; it included the most used resistors, capacitors, diodes, dip switches, pin arrays and also dual side copper plate for PCB milling). They told me that from Taiwan it was not possible to ship so few pieces for them and asked me to complete the list with all the components I was expecting to use. I included also AVR 328P, shif t registers, optoisolators and many more). And they sent me about 70 Kg in a box with 1000 (one thousand !!!) of every piece. I suppose that I don't need to buy this for the next few years ...
Until now, for a lot of practice reasons I use Eurocircuits for PCB prototyping and small production. It is true that they have not super low pricing like China, but the service is exceptional and if you consider the "PCB at 5$" from China, ask for a real cost analysis for example for an Arduino shield, add the shipment time (7-10 days after they build), add the custom taxes price of Eurocircuits is truly competitive.
Enrico
