Apple controls the price of their hardware. If you have a school affiliation, you can get a price break on the Apple site in the education section.
Other possibilities are places like macmall.com or macwarehouse.com, where the price of the computer is the same as Apple's price, but they bundle a printer, extra memory, or software at the same price.
If you're looking at used or refurb, go to shrevesystems.com. They are the oldest Apple 'remarketer' there is. I've dealt with them several times with good results each time.
Welcome to the bright side of the force.