you can buy cheap parts .... theres alot of stuff on Ebay some is some ok and i get good deal on stock OEM valves . i use new valves in most all stock head rebuilds as it takes more time to clean the old valves and re face them and stem them only to end up you may only have a 1/2 set of valves that are ok used valves ... you have to know what the cheap parts can take . valve train is not a place to go to cheap .when valves come apart or fall down from busted springs . pistons will drive valves backup in to the head or die trying this is when things get very ugly