Under no circumstances buy mining equipment with your 3500 bucks!

The difficulty has been skyrocketing! Say you buy the miner today and even if it arrives in a week (which is not the usual case) your revenue will exponentially shrink from day to day you operate your miner. To verify this google for a bitcoin mining calculator that has something like a "difficulty increase" option.

Buy bitcoins with your money now and hold on to them.