That's a good price but it's not like it's $50 or something. TB only retails the head for $275 in the first place.
Their retailers also sell it for $275. There HAS to be built in profit for the retailers. I recently had my TB head fail. TB woudn't warrenty it, but the shop I bought it through offered me a discount, say it was 10%. $27. Brings you to $250ish, but the shop still has to make money. So you figure a small shop is probably buying them for not much more than $200 with all the bits (cam, rockers, gaskets, whatever else).
Strip out the extras, sell the cam individually for, say $50, rockers for $10/pair save the rest for shop stock, and suddenly the guy is making plenty of money.
If it's a bigger shop, I'll bet they get everything a hell of a lot cheaper.