I picked up[a Roland PC200 controller for $40... and I've seen other older "output only" models (Eidrol, etc) for about the same
IK Multimedia just had a killer deal on SampleTank.... uh... Xsomething $49.00 and it ended up being 7 additional 'libraries' (you're pick, loops or instruments)
check it out... i think it ends today (unless they extend it again)