Brand new they'd be about $180 together ($80 for the CPU, $100 for the card). The 2GB 750GTX goes for a good bit more, and Amazon shows the 1GB used to sell for $100 when it was in production.
eBay shows they go for about $60 each if they're used. On Craigslist, you could try $120 and figure you'd get around $100 total. If you sold them for $120 on eBay you'd end up with about $100 and CL buyers know that.