Costs all depend on the quality of the springer. $500 -$2000. You will also need to budget a new front brake set up it'll cost you $250 plus. You'll also need a new set of risers for your handlebars and possibly a new set of bars, if they are 1.25 because the space between the risers is different then on a telescoping triple tree. 1.25 bars taper down to 1" for the riser clamps and will be too narrow for a springer. You will need a headlight bracket aswell.
Not my bike just one I came across on the forum a couple of years ago I liked the rear fender so I took a copy of it for possible future reference, so I've no idea of cost or anything else, looks good though.