Coinbase charges 1.49% fee to buy, once that goes thru and you have BTC, you can send anywhere you want (Polo,
Binance /
HitBTC, Hitbtc has deposit fee now)
Then you can buy most popular alts at those exchanges, each of them have their make/taker fees too, i think usually between 0.1% - 0.25% fee per transaction
I would suggest checking out Gemini though, you can do the exact same thing with Gemini for 0.25% fee only, rather than Coinbase's 1.49%