Two new wheels, tires, new chain and a tuneup will cost you at least $500.

A new 7.5 is only $1k. New and improved parts, a +5mph for new bike syndrome, and you get a new bike!

I'd say buy a new one, and keep the old one around until you're ready to sell it. Or you can just convert it to a fixie in a few years just to keep it around.