It could cost anywhere from $700-$2500 depending on what route you wanted to go. Used parts or new. 4mm spacer plate or 4mm cut domes. It will also depend on what you want to spend on Bolt-ons, Transmission mods,carbs, Extra welds and bearings on the crank and then pipes to match your port. $2400 is what I spent on mine, but I bought everything new. and did all the reliability mods. Don't get discouraged by that price. I know it can be done for under a grand.
Oh....by the way, It was worth every penny