What would a used ECM for 1994 Oldsmobile cost?

Try ebay. You may find one for around $100. There are also ECU rebuild outfits that charge around 200-300 depending on the computer. Alex

a used one at a scrap yard, maybe $40.00-$50.00,maybe less? can you find one that's still good from sitting in a scrap yard for XXX,maybe? If you buy one at a local parts store,rockauto.com,or ebay it will most likely be a remanufactured one. parts stores are around $130.00 plus you give them your old one or pay an extra fee($10.00 or so) for keeping your old one,BUT you have to do this first also>>A-1 CARDONE 77-3247 {#16183247} Remanufactured; Does not include PROM. ""The PROM(s)/CALPACK must be transferred from the original module to the replacement module. Additional relearns (theft, crankshaft, idle, etc) may be required"". before looking for one,get the numbers off of yours first to match replacement!

Before purchasing any parts - strongly recommend getting another option from a mechanic that's familiar / experienced with OBD1 operating systems.