I'm building a SG clone from a kit. Ephiphone makes an SG guitar - "The Epiphone SG Special is an incredible way to get real SG tone and styling without breaking the bank. The carved SG-body shape and SG sound at a "workingman's" price."
http://www.epiphone.com/Products/SG/SG-Special.aspx
Knock-offs and kits make for more affordability.