I want to upgrade from Vista to Windows 7?

I have Vista Home Premium 64-bit and I want to buy a version of Windows 7. I have three questions to ask >>>

A) Which version should I buy?
I'm in college, so should I go for the student version, or what? (is there a student version?) And what about 32-bit and 64-bit; what's the difference?

B) What must I do prior to installation? Do I have to wipe my hard-drive?

C) Where can I get it for the cheapest price?
I might buy Windows 8 a year from now, so I don't want to spend a lot of money on 7 knowing I'll only reap the benefits for a year before ditching it. Where can I get it for, say, less than 50 dollars?

[Image: 28efec54fc1ac6c067de42f0c9bde684.png]
[Image: c967e5721f5ca1d3f91fa99bc0e6ac37.png]
[Image: dd62addc4e1f10021a16b7df1922316d.png]