Find likely cheaper ways to buy a Mac, Dell, or other computer than just walking into an Apple Store, BestBuy, etc. 

Apple products, including Macs

Buying using your Cornell-based email address gets you access to Apple's education discount:

• http://www.dfa.cornell.edu/cms/procurement/secure/cu-employees-students/upload/apple.htm

Above link from <http://www.dfa.cornell.edu/procurement/supplierlist/computers/desktops-laptops/apple.cfm>, July 20, 2015.

Expect the same pricing as one get's at Apple's own Education store:

• http://www.apple.com/us-hed/shop

Microsoft Windows-based products

Dell

For the cheapest Dell purchase, consider using Dell's "refurbished" offerings:

• http://dellrefurbished.com/

Or buy brand new through Cornell to afford you a negotiated discount, but specials you find on your own can sometimes be better deals:

• http://www.dfa.cornell.edu/cms/procurement/secure/cu-employees-students/upload/dell.htm

Above link from <http://www.dfa.cornell.edu/procurement/supplierlist/computers/desktops-laptops/dell.cfm>, July 20, 2015.