Seen "kits" on e-bay consisting of pistons, rings, wrist pins and gaskets for around $100, to complete jobs including new heads, cylinders, ignition going for a couple grand. Depends on the amount you want to spend.
I spent almost 900 on screaming eagle parts. I bought bolt in cams, new cylinders, 10-1 forged pistons, and a complete gasket set. I'm not looking at resale, even though the bikes a 2002 I had to do it, but I would guess it would hold its value as well as any other harley.
I am in the middle of collecting parts as we speak. So far I have purchased a set of Buell 1200 Cylinders/Pistons/Rings, and will be taking the bike apart next week for the conversion. This is the cost breakdown so far.
1200 cyl/pistons/rings - $200 - from sportstor.org
Headwork on stock heads - $65 - local indy/machinest
Gaskets and Labor - $250-300 (estimated) local indy
I will probably end up spending about $600 - $700 total after you count the carb rejet, and other odds and ends.
This (of course) does not include the price of the LongShot exhaust and SE Breather Kit I already installed myself earlier this year. That was a cost of $270 (pipes) and $70 (breather kit) which brings the GRAND TOTAL up closer to $1000 roughly to do the conversion and pay the "Harley tax"!
I spent 350 bucks for boring, Wisco pistons and gaskets. 100 bucks for new ingiton & hotter coil. I already had the dyno-jet kit , S/E slip-ons and the S/E A/C.
I did my own head work & instalation. After 22,000 miles on my conversion I had a free Dyno run & my work cranked out 65 HP. Prices are higher now. I also would say get new cylinders the shop I use almost messed up my stockers and they will not be usable when they are worn out.
The price of my 1200 coversion was $998. Labor included. The workmanship done at the dealership was A-1!! Two years later, and not a sinlge problem. Runs/scream like the dickens. I went with 10:1 pistons and wiseco cams. As far as resale is concerned, I feel as though it will only increase re-sale value.