As a consumer I agree the evaporator is an expensive repair; I had that done on my '94 caravan several years ago. It has been worth every cent though. OTOH I was really screwed by a dealer when I had the fuel filter and gas gauge sender replaced - they ended up charging me over $1000. When I picked it up the van died halfway across town because the mechanic had crimped a fuel line. Towed back to dealer. Repaired again. Later I find out most shops replace the gauge sender and fuel pump at the same time and they are usualy sold as a unit. The dealer would never admit they made an error nor would they reduce the labor cost for replacing the fuel pump too. I'll never do business at that dealer again.
-Hal