there is no way that the heads and valves are being replaced for the price. He is totally snowball you.
600-700 for a timing belt and 600-700 for the head gasket.
I paid a honda dealer 2400 for new timing belt, head and valves once on a 92 Prelude si.
here is an interesting post on oil useage:
http://forum.planetisuzoo.com/viewtopic.php?t=7033