I have to commend RebelBooks because they saved my life. I needed unlv merchandise and they are open later than the bookstore usually is.
Honestly, textbooks used to have a few dollars difference, and now it doesn't matter which bookstore you go to because the prices are all the same!
Most of the time, at checkout, they have an option that you can donate something to charity, which I love. Sometimes you have to buy the item, but usually it's cheap and worth buying like a shirt.
Basically, it doesn't matter what bookstore you go to, it's all pricey! Just GET YOUR BOOKS!