Here's a video on how to lower your fees on Coinbase when withdrawing. Pro Tip: Don't buy bitcoin in the retail customer side; buy from their GDAX trading exchange. You're only paying .25% on your buys.
And if you really want to be smart, you might just avoid Coinbase altogether. I've been experimenting with Gemini to buy bitcoin. All their transfers are free, deposits and withdrawals, with just .25% on buying and selling.