I looked for about the last 2 weeks on CL. I found a ton of them for everything, but a 6 hole Chevy. The sets I did find all had street tread and they wanted $1,000 for them. I found a bunch of good looking Ford wheels. I don't know why the Chevy wheels were so hard to find. I know it took about 10 minutes to find a buyer for my old tires on CL.if you have the time and patience to dig on Craigslist. New factory take offs come up regularly. folks that get aftermarket wheels/tires. then need to sell their brand new tires with factory aluminum mags.
most times they can be purchased for less than cost of new tires alone. then sell your old set of wheels to recoup some costs back. even if your old tires are worn out, if you have aluminum mags, some one will want em.
net costs will be a fraction of new tires alone ... plus you've upgraded to latest aluminum mags too. just upgraded to a set of 2012 Dodge 2500 8 lug aluminum mags with Michelin tires with no miles for $750. then turned around and sold my old set with 80% rubber (Michelin) for $550 including 2006 factory aluminum rims. since rims were worth $375 without tires and had an easy 40k miles remaining... buyer was real happy.
final costs was $200 to upgrade to latest Dodge factory 8 lug aluminum wheels with new Michelin 275x65Rx17 E rated tires. everyone ended up happy, especially me...