Bought a used 2000 lumina. Has power windows and locks but didn't come with keyless remote. How can I get one and program it for my car? I guess a dealer would be COST-PROHIBITIVE.

No guarentee that the car has the receiver. Mine does not, dunno how hard it'd be to put one on. If the wiring is all there then just get the module: about $100 from my local dealer.