The cost of pistons and rings with a blanceing, bearings, gasket kit and for good measure, a oil pump. Price these out and the possible 3.58, 360 cube crank and you'll have your bill.
The problem to putting a number or price tag on this is the price charged by shops in different parts of the country. Then again, the shop itself can vary alot. Even in my own county, the difference can be larger than one would excepct.