4. GDAX - When you buy Bitcoin there will be a 0.25% fee and a 0.30% fee for when you buy Ether or Litecoin. Deposits and Withdrawals are Free.
If a limit buy/sell order is used, GDAX does not charge a fee. Additionally, the TX fee is handled by GDAX making it totally free. The downside is the week delay if you are doing a ETF from a bank, but it's the cheapest way.