They are cheap, and quite easy/fast to replace. I did the crank and cam seals on our 2004 Civic, about five minutes to do both of them. They came with the timing belt kit (with water pump, tensioner). I already had everything off since I replaced the cylinder head. That said, the camshaft seals tend to leak more often than the crank seal.I was planning on getting everything replaced as listed above but was not aware of camshaft/crankshaft seals. Are they something that fails with regularity?