Hi, I have been working on a robotic arm reprap here:

[reprap.org]

and I was also thinking about the extruder I am going to use as well as the plastic. I have tons of 12 X 24 X 3/32 plastic sheet lying around, and I wondered if I could cut it into strips and use it to extrude. I could use this copper pipe fitting:

[www.grainger.com]

and squish the large end down to a 3/32 X 0.3 slot. I would cut my plastic into strips 0.3 wide and feed it in. Each strip would be good for 0.675 cubic inches. And I could make 40 strips from one sheet, or 27 cubic inches. These sheets of plastic only cost me 3.50 on amazon, so the cost would be 12 cents per cubic inch.

The extruder nozzle would be 1/8" diameter which isn't super precise, but it is good enough for me. It will also print faster.
I just need to wrap some Nichrome wire around it and cover it with jb-weld. Do you guys think this would work? It would be nice to use some plastic that is much cheaper than filament.

It sounds feasible.

I'd consider making a heater barrel with a rectangular center hole. Perhaps soldered together from brass bar stock. You could taper the hole so that it was 1/8" square at the bottom and 1/8" (3/32" + 1/32" for clearance) by some convenient width (1/2"?) at the top. If you know someone with a lathe you could turn and thread the bottom for a standard nozzle.