I know its not easy but use a private wallet and try to stay away from the big boys like Coinbase
because they are not only charging too much in fees but are giving you a poor exchange rate that they
try to hide why you buy or sell
if you are in the UK this it might be worth checking out
https://bitbargain.co.uk/buyit shows the price for small amounts of BTC like 0.001 and also displays the rate it will be costing you.
Please, please , please stay away from brokers because they are printing coins internally and are worse
then the old bankers in my book