Is GAHH the only seat cover replacement choice?
 

I spent some time at an auto upholstry shop today. They recommended GAHH leather replacements for $2500 including parts and labor — primarily because they could not find another supplier (who they believe makes a quality product).

Is there a cheaper alternative that doesn’t look cheap?

Have you looked at Lseat? That's what I installed.
http://986forum.com/forums/boxster-general-discussions/81934-reupholstering-boxster-seats-lseat-kit.html

+1 on Lseat. Comminucations are a bit slow but the skins look and fit great.