Coinbase is a joke really. Think about investing in some mining contracts, like on Genesis Mining. You'll get a steady daily payout in a range of cryptocurrencies of your choice. Then you can just go and dollar cost average your earnings into smaller coins or whatever you want on the exchanges, like Poloniex, Bittrex, Bitfinex etc., or just hold what you get mining in your personal wallet. I'm not saying go all in but I think it's good to complement regular buying through Coinbase or whatever.
I don't think now is the time to really be buying a lot though, the crypto market as a whole has already done it's hockey stick pattern thing. Personally I'm holding back from putting any more fiat in until after a major crash, or at least after August 1st. Just holding on to what I have for now.