Okay, so I maintain that anyone should get Windows 8.1 over Windows 7 at the normal price of $100, but here is a chance to get $15 off 7. Use the promo code EMCPFWP24. This is a Newegg subscriber deal, so you may have to sign up for their newsletter before the promo code will work.
Note that the code only works for the Home Premium version. I tried to apply it to 8.1 Home, 7 Pro, and 7 Ultimate just to make sure.