Attached is information from an article subtitled “Our Quest: 500 Hp for $4,000 on Pump Gas” out of the Alternative Engine Series in the May 1998 issue of Hot Rod magazine. Rob Chilenski of Stage 1 Automotive builds a 464 cid Buick that does just that in the article. The engine was estimated at 501 HP based on an ET of 11.59 at 117.2 from a 3950 lb. race weight Skylark. The heads where Stg 1 Level 2 by Greg Gessler, and the combination used a GSCAs Hemi-Killer cam. Scotty Gudagano from Pee Gee Performance did the machine work. Below is the detailed carb to pan parts and prices from the article. Its over 20 years old, but you can get an idea of what is needed from it. I'd add at least 25% more for parts these days:
Block—block core, bore, bake and freeze plugs $420
Pistons-- JE forged 10.5 : 1 .038" over, includes lightweight pins $649
Rod bearings--Clevite 77 # CB762P $42
Rings--Sealed Power # R-9798 $127
Heads-- Gessler Level 2 complete $ 1,195
Pushrods-- $70
Crankshaft-- Stock .010 under $80
Main Bearings-- Clevite 77 # MS908P $64
Camshaft & Lifters -- Lunati 214*-241* GSCA Hemi-Killer includes lifters $200
Cam Bearings-- Clevite 77 # H-1361-S $20
Timing Set-- TA Billet # 1524 $109
Intake-- Edelbrock Performer $238
Carb-- rebuilt Q-Jet $150
Ignition--rebuilt GM HEI $100
Oil Pump-- Sealed Power High Volume $65
Front Seal (timing cover)-- Federal Mogul # 450446 $9
Rear Seal-- Fel-Pro # BS40012 $14
Exhaust Headers-- TA Performance $269
Buick GSCA Membership-- $30
Total costs of parts and machining listed in the article was $3851. Shipping and non-machining labor costs were not included, and may vary depending on the area. Additionally costs should probably include balancing the assembly at a cost of about $150 and installing the cam bearings at a cost of around $30. This would allow the rest of the assembly at home for a total cost of $4031. ARP rod bolts ($60) and reconditioning the rods ($70) might be another consideration that would push the total to $4161, and I did not see a cost associated with pressing the pistons on the rods. Not a bad price for 500 Hp on pump gas in any case.