Ain't worth 10K even. The car does not appear to be stored correctly and the dry rot and corrosion you CAN'T see would worry me. This car will need a new headliner, and some other rubber bit refurbishments. If it hasn't been started in 23 years, it certainly won't be running right anyway.
Personally, take your 20K plus and plunk it down on a similarly situated 4.3 mile NEW 2010 Camaro. That's what I would do. The new Camaro would be far and away a better deal. Some other yutz can buy that and restore it, because that's what it'll need. Then you have to plunk down some more money for IROC rims...where does it end?
2010 2SS/RS Auto, Sunroof, Engine Cover. Transformer Edition package.
2013 ZL1 ragtop #5478. 1 of 54 CRT M6 'verts.