The parts arn't that expensive, if you decide to rebuild your head yourself. Honda valves are like 20 bucks each. If memory serves me it's like 18 exhuast, 22-23 intake. Valve seals are like a buck each, valve guides come in at a few bucks as well. Ooops but since you asking for labor... going rate for labor is generally 70 bucks an hour, depending on the job. Typical rebuild time is about 1.5-2 hours if your head is already clean and you know what you're doing.