i paid $250.00 for my gtp heads at a local salvage yard an picked up a set of trickflow valve springs off ebay for $50. I also got my edelbrock intake off ebay for $275, so I'd say $500 sounds like a better deal to me.
Well alot of that depends what you consider a good deal. Is it a real GT40 tubular intake? They have been going high on Ebay. I just sold one for $545. The 2 I watched before that went for over $500. Are they worth that? Well its supply and demand and what someone is willing to pay for them. An Explorer goes for about $200 all day long on Ebay. You can find used GT40P heads for about $250-$300. You can get brand new GT40P heads for about $500.
Would I pay $600 for a Explorer GT40 upper lower and GT40 heads? - no F'N way.
Would I pay $600 for a Real Tubular GT40 upper lower and GT40 heads? - Maybe buy them and separate them on Ebay.
I was offered a full exploder motor for 400 bucks, talked him down to 350, but now I have no room for a complete motor, I am hopin to get the heads and intake for 200 bucks. That'll be a hell of a deal