Fred, there is a lot that goes into a quote such as what quality of equipment, size of filter, type of decking, automation, etc... Best thing to do is first to decide what you want in your pool. There are many treads in here of new pool builds and equipment treads that can give you many ideas, such as do you want SWG, infloor cleaners or suction cleaners, sand filter vs cartridge vs DE filters, ozonators or not, variable speed pump vs single speed, Pebble interior vs plaster, etc... There are advantages and disadvantages to each choice which you can readily find in this forum. Next step is to then get several quotes from reputable pool builders with emphasis on reputable. Research the BBB and your ROC board to make sure they don't have a lot of complaints. Then compare the quotes and make sure that they are comparing apples to apples.
That said, 50K seems to be a lot for a basic pool. For 55K here in Phoenix, we got a quote for a pool with a spa with heater, vs pump, LED lights, Pebble Sheen interior, grotto and slide, acrylic decking.
Le.