I'd take a shot at getting your $79 back. The additional $3200 they recommended above the $800 for a water pump bothers me considerably. It appears that they were doing a bit of science fiction writing rather than honest estimates. I'd bet that if you had the work done you would have had the water pump replaced and also a new fan clutch assenbly for well over 1K$.
Too many times I've had one of my kids or a neighbor get an estimate from somebody for a major replacement when the trouble was something very minor and very obvious. Case in point: my daughter was towed into a shop when her alternator light came on. Estimate was for a new alternator. When I looked at it when I went to pick her up, the screws had fallen out of the brush assembly and it was hanging by the wires in plain view. I bought two screws from a very ashamed shop owner and fixed it with my swiss army knife.
Keep the water pump as you will eventually need it and you'll be glad to have it on hand.
'85 300 SD, 165K-Sold
'88 300 TE, 165K-Sold
'64 Porsche 356C Cabriolet
'86 560SL 124K Miles
'94 320E Wagon, 74K Miles