EDIT: 6/6/18 - fixed broken links; updated link to part 7
The BOM is in the attached spreadsheet (and Github) but I haven’t copied it here: I suspect that it’s only of interest to those people who want to download it. There are two copies: the original parts list, and the updated one with a DC-DC Switching Regulator swapped for the LM7805.
Wherever possible I selected parts available from uk.farnell or cpc.farnell but they don’t carry everything needed so some parts have to be acquired from Digikey and Mouser: in all cases manufacturer and supplier references are given. I have not used eBay, Amazon, Bangood and the like as sources as I, personally, don’t trust those. I’ve given both required quantities and minimum order quantities and links to data sheets.
At a rough guess, I’d say this is costing me around £150: I’m buying other things that I need to build this such as crimps, heat shrink, connectors, insulating bushes, PCB mounts, thermal paste and so on, and I have pretty much no inventory of the parts to call on (just the one, I have a few LM7805s.) It can all be weeded out of the BOM if not needed. I’ve also gone with an expensive Arduino solution: it could be built without that, the thermistors (and associated resistors) and the INA260 (the trace would need to be bridged) - just attach a multimeter to the IMon pin on J4 or across the output - or using an Arduino Pro mini or Uno with a 2x96 LCD.
The parts list does not account for an enclosure yet either. The total part count is 65 parts (including all the extra bits I need) with 119 pieces, plus 2 PCBs and 1 enclosure which feels pretty reasonable to me.