1993 Honda Accord Smokes when starts from exhaust pipe

Every day when starting the car, blue smoke comes out of my car. After a while the smoke turns white than decreases in output of smoke.
I have talked to people and they said that the problem could be with the cylinder head valve seals or weak or bad engine piston rings,
i would like to know average costs to get that fixed and oppinion on what to do and what else could be wrong.