Side note: I'm in the U.S. Anyone know how much they take in taxes (approx.) when you cash out? I've heard people saying around 7.5% all the way to 47% 
Depends on how the US handle taxes, but in many countries they tax it based on how you earned it. For example, over in the UK we have income tax, which is basically how much you earn in a tax year, and depending on the threshold you are in depends on the amount you get taxed. I believe it starts off at 20% for those over £11,000 ish. However, I do believe the USA are one of the countries which determine the tax based on how you got the Bitcoin. For example, mining, selling goods, or purchasing Bitcoin from an exchange. In your instance, buying it from an exchange, I believe they tax it as capital gains tax, on the amount of profit you made on the purchase.
You shouldn't take legal advice from us though. If you are serious about investing in Bitcoin or any cryptocurrency for that matter its probably worth either learning about tax yourself or getting in touch with an accountant.