The rings themselves arent that expensive, but dont order them until the engine is torn apart and measured because if youve got alot of bore taper or out of round it may require being bored over, needing oversize pistons & rings. also plan on new rod, main and thrust bearings along with new seals, head gasket etc.. may as well rebuild the head while its apart. Its basically a complete engine rebuild. Although it is possible to just slap a set of rings in and hone it. But regardless its very labor intensive and thats where a majority of the cost comes from