There are tons of used high quality headers out there for sale.

Typical pricing:

TODA - $500-$700 pending on condition
SMS-P - $600-$750 pending on condition
Hytech - $550+ pending on condition
RMF Narrow - $350-$500 pending on condition

You can find a nice used header, for about 50-60% of the new cost. Just keep your eyes open.