HELP!

Our 1983 Volvo 240 GL went in for a few minor things, like an oil change, replace tail pipe, and a request they check for signs of leakage due to some stains on the driveway. Result: a recommendation that we replace the front and rear seals, replace a leaking water pump, replace the timing belt (because we don't know when this was last done), and replace the head gasket. The quote for this work was astronomical.

I've authorized the repairs they felt were critical, which included the water pump and the front and rear seals. The mechanic told the "service writer" that the head gasket "wasn't that bad". The price they had quoted for each component was in the $100 to $500 range! So I've asked them to hold off on the timing belt, and the head gasket.

Now the questions: It looks like to do the timing belt (which was done once in the prior owner's ownership of the car, which now has only 80,000 miles on it), they have to do a lot of the same disassembly as they do to get to the water pump. Should I just go for it? If so, anyone know how much this should cost?

Second question: If the previously BAD seals are replaced, it strikes me I could be at risk for the head gasket to go ahead and fail completely; but surely this isn't a $500 job?

Thanks for your input.