What about using an exchange? Imo, that's definitely the safest option. Many of the cryptocurrency exchanges have the ETH/BTC markets, like for example
CoinDeal. Isn't that the most reasonable and safe option?
Absolutely, but you failed to understand that the OP is a scammer. Use your logic.
Everybody knows that selling on exchanges is easy peasy once you get the initial things done. We see scammers like these everyday on this section of the forum so be careful whom you are trading with. Remember that making new account to scam people with same tactics takes minimal effort and people actually fall for them.