If you buy everything new you are looking at over $3000. If you get used heads you will save a few hundred bucks. I just bought me some from steen with VT stage II cams and it was $2775 for all new PI parts, intake, all gaskets and needed parts for swap and also stage II P&P and stage II cams from VT. That is the best price I found anywhere. Install will run you another $700 to $1000 and then you will need tuned. It is a big venture as far as cost but I decided to take the leap. I'll post in a couple of weeks what I got from it.
Rob
Cams: $525
Springs: $200
Gaskets (Front Cover, Upper/lower Intake, Head, Header, Valve Cover): $150-$200
Heads (mine were Patriot w/no core): $1295
Head bolts: $50 (headbolts.com I believe)
Labor: $800 - $1000 depending on shop.
If it's a Windsor (99/00) motor you'll also need cam bolts/spacers & sprockets: $80-$100. If it's a Romeo (01+) you won't need these.
That's all I can think of at the moment, so you're in the $3,000 ballpark like was stated.