Do it yourself if you can, if not; Valve seals are around $25; But 5 hours of labor is a bit steep. I thin you can find someone to do it for around $350 if you look enough. Most mechanics go by the "big book of labor." More often than not, This book is quite wrong; after all, it is just a guide. A skilled mechanic can usually do a VS job in about 3 hours or so.