valve ticking?

wow thanks! would it be worth it to try cleaning them, not replacing the valve cover gasket, seeing if that works, then doing the valve cover gasket (a week or two later) or should i just replace them anyways just to be safe? is it bad if i buy the cheap ones?

how many do i need? i went to the car store and they said i need 8 but that ended up costing over $100 and they were cheaper then the ones on rock auto :/