Pumps are not that hard to change out, but as Jason says consider just replacing the motor, on most pumps this can be done without disconnecting any of the plumbing. As to replacement pumps, I would look at a 1HP 2 speed, but we need to know more about your pool to give a good opinion, do you have any water features, spa area, heater either conventional or solar, is your pad far from the pool or located at an elevated location, etc.
Ike
p.s. as to pricing it sounds like the pool store is getting you twice first on mark up then on installation, it really is not that hard to install as long as it is the same voltage as your current pump, anyone handy with plumbing and wiring should be able to do it if they pay attention to what they are doing. For comparison I bought my current pump in my signature off ebay a month or two ago for $350