Bravada would not start.

My 97 bravada would not start. Since I live in an apartment building I cannot do any work on my car since I moved out from the parents house. Brought it to a shop and they said the fuel pump was shot. They had to pull the tank down and put in a new fuel pump. ended up to be $900 after tax for all parts and labor. Not like I had a choice to do it on my own, but just wondering if that was a rip off or sounds like a normal price for that job. The mechanic mentioned that he shopped around for a cheaper pump to lower the costs. Would this be a used fuel pump?

No, he likely spent some time checking with his suppliers to get you the best price on new parts. Most places have a 90 day warranty on parts & labor with some parts having more warranty.
Most shops have to charge what seems like high labor rates until you consider the overhead costs of wages, taxes, Social Security, uniforms, tools & supplies for the employees. Add some schooling, insurance & benefits you have to offer to keep top notch mechanics and you have some real financial challenges the DIY'ers don't have to endure but the paying customer gets expert repairs & service a novice DIY'er doesn't.
Pay very close attention to how the car performs and if you have any issue with how it starts or runs, consult the shop manager asap.