i guess i'll be the 1st to chime in on this one.....
This is just my story, but i did my ENTIRE PI swap, for less than $700.00
This includes the head install kit, compete heads with cams+valve covers and all fluids to complete the swap.
Heads+Cams+Valve Covers $350.00 E-Bay
Machine Shop Work (mill heads, new stem seals, pressure check) $120.00
Intake $25.00 (have a friend that works at a parts store, he owed me a favor)
Head install kit (Joe Cooper Ford, Tulsa O.K.) $78.00
Misc. Hardware bolts for timing cover, heater tube, ect. $70.00
the rest was oil, torque converter seal, antifreeze.
I waited 6 months for a steal on heads, found a lot of good sets, but were all going high $400 or more! just kept bidding my max bid, finally won an auction, but it ended at like 1:20 in the afternoon, so i don't think the other bidders were watching and I won.
The intake was also another price chopper, that intake is normally like $300.00 or so, but i was owed a favor and got it for $25.00
Just my story, the PI heads+cams+intake swap made a HUGE difference! it's a whole new car, pulls soo damn hard up top now!
I used Windsor PI heads, hence me having to use the valve covers and different timing cover studs.