Your starting with Coinbase is a bad premise.... There are better ways to obtain your bitcoin such as localbitcoins.com.

I have never bought a single bitcoin, nor do I intend to, but let's just say I've had a lot of bitcoin.

Edit:

There is more to worry about the price fluctuation in bitcoin anyways, then compared to a small percentage in buying.

Hopefully, it will go up.... but, as recent days as shown us, that is not always the case.