1999 Plymouth Voyager Possible blown head gasket

My 1999 plymouth was over heating and ended up dying. We towed it to a local mechanic who told us the head gasket was possibly blown, but he also said he didn't really work on engines and we may need an engine. We have since decided to purchase a new van, but our teen daughter needs a car. We are thinking of seeing if we can fix it so that she has something to drive until she can afford something she wants. Do you have any idea what kind of cost we would be looking at to fix this. We don't want to spend a lot of money because the van is not worth much.