My really cool aunt says that she will sell me her 1959 perfectly restored Corvette for $15,000 when I graduate from college in 7 years (on time, with good grades) because she will be really old then and she thinks I'll take good care of it. This is an incredibly good deal so I don't want to mess it up, and I don't want to take any risks with the money. I've decided to put the money aside now in a risk-free account earning 5%, compounded annually, and not touch it the whole time. How much do I need to put aside today?