It's never a sure price when these things happen. Spun bearing means you might as well rebuild the engine seeing as it'll be pulled apart anyway. You'll have the price of the parts (bearings, pistons, piston rings, rods etc.), then labour will be split into things like removing and replacing the engine (which I've seen quotes of $1000+ for this), then machining costs and assembly (around $1500 for just assembly). There's no straight answer but these are the kinds of figures your friend can expect. Along the way there will most likely be miscellaneous costs for random bits here and there.