Within the last 9 months I've replaced both passenger side window regulators & the a/c compressor. You shouldn't need to replace the window motor, just the regulator is what was broken on mine. I got mine for less than $60 each with shipping at Walker's Renton Mitsubishi online.
I had a similar problem with a wobbly clutch on my a/c compressor, so I bought a clutch for it. When I pulled the old clutch off, I found that a chunk had broken off of the end of the shaft so I had to replace the entire compressor. Pricey bugger-found it at a local import shop for $408 + tax, replaced it myself, then had a shop evac & recharge the system for another $160. I'm not sure if the wobble was caused by the broken shaft or if the clutch bearings went out & caused the shaft to break.