Cheap Alternatives to Flex Sensors for Gesture Glove Project

I can't see how you can realistically do anything if the budget is so tight, and you've got 19 days to order, prototype, and prepare a demo. This is called leaving it too late (you and your team have only yourselves to blame; don't think you should entirely blame the team, since you're involved too).

Instead of five sensors, you could reduce effort and cost by fivefold by converting the project to a gesture mitt that senses only one movement.

You didn't state the aim, but if it were me on such a timeframe, I'd move the goal and detect different objects rather than grips, or detect grips by picking up different objects. For instance, conductors on the forefinger and thumb, each connected to one end of an ohmmeter, or to a microcontroller ADC. Then, have cubes with two conductive surfaces on opposite sides, wired internally with a known-value resistor. When you pick up an object, the circuit completes, and the ohmmeter will register a measurement. Cubes with different resistors will all be distinguishable from one another.

You could also experiment with trying to make cubes that vary resistance the harder they are pressed, but that could be a phase two.

Bro, school exhibition announcement was done on Monday, that's why we are actually on time for the school but in real scenario we are not, by the way this is extremely good idea, but cost is not that tight, I remember once tesla coil was made and it was actually mind-blowing for judges, I want to tell that judges are too dumb to understand these smart tech things (don't mind) ,they only make things win which look like magic , even if low effort has been given. And its easy to make

Bro, school exhibition announcement was done on Monday, that's why we are actually on time for the school but in real scenario we are not, by the way this is extremely good idea, but cost is not that tight, I remember once tesla coil was made and it was actually mind-blowing for judges, I want to tell that judges are too dumb to understand these smart tech things (don't mind) ,they only make things win which look like magic , even if low effort has been given. And its easy to make

You need a project plan, and at some stage you need to have completed some research, then come up with a potential design that won't stretch your entire plan beyond its end date (i.e. keep perspective in your goal/objectives), place your parts orders, build your prototype, experiment with it, and iterate if needed, perhaps in a phase 2, but demo what was successful.
You can't go from zero to hero without some plan and experimentation.

Case in point: I experimented with making my gloves touch-capable over winter. No point if the project stretched beyond winter, so my project deadline was clear. I knew I had to order quickly and try to experiment fast. My first prototype didn't work. The second one did, to an extent, it was usable although not great. Still, I met the self-imposed timeline. If I'd shot for 'killer' and 'next-level' it would probably be next winter by the time I'd have completed, and sometimes having something to use or demo fast that you can iterate later, is better than having nothing to demonstrate for a year.