Hodlhodl[1] has a 0.6% fee, which is pretty low enough. It's a peer-to-peer exchange though, so watch out for scammers and all that, and just pick the BTC buy/sell price you're happy with. It's not as easy to use as exchanges such as Coinbase and Kraken, but the reason why exchanges like Coinbase and Kraken have kinda high fees is because they're so easy to use and that the liquidity is pretty high(which is a good thing).
[1]
https://hodlhodl.com/pages/faq