Clutch can go for up to $1000 depending on which parts and model of car you have. Dealer labor is based on a "flat rate" book while an independent garage will charge what it wants. If you have an SH it takes longer than a Base.
Now to the valves-why did they fail is the Q here? If you overreved the engine then the head has to come off to properly inspect and repair. There are remanned heads from Honda and else where. How much-call a dealer. Labor+same as the clutch.
Whatever you do-do it right. The head is not hard to replace but must be done according to the Helm. A clutch can be done at home too-if youu have the right equipment and time. These projects can take upwards of 8 hours each.