rmac, if you go with Kraken as an Exchange you could lower these fees as low as 0.15%. With GDAX, if you are the market maker (in plain english, if you place a limit order) you could even get to 0%.

The withdrawal fees on Kraken and GDAX are very low if you use a cheap fare coin like LTC (0.0001 LTC) or Ripple (0.0001 XRP). So with GDAX, you'd only be looking at the transfer fees. You can use GDAX.com if you have a Coinbase account, Kraken needs a separate registration.