Installation of laminate countertop - is this price reasonable?

We just had a laminate countertop installed in our kitchen. The countertop was shaped like an L with an overhang (on the L) to the other side where we can sit along one side of the L. The countertop was approx 30 inches deep (I bought sheet laminate that the installer glued (he build the surface from plywood) and bevel edges to be glued). The total length in linear feet of the countertop is 20 linear feet. Our wall was somewhat uneven so the back had to be scribed. Our installer originally told us the countertop should not cost much more than 1500 but now he says that it took longer than he thought and the price is 4500 (for the work + materials). Are we unreasonable to be shocked - I mean it is laminate. He did cut out the hole for the sink for us (we installed the sink ourselves though) and screwed in the bottom cabinets to the wall - there were 4 bottom cabinets there (we put the cabinets together ourselves beforehand).