It doesn't necessarily have to cost money to get someone to offer a second pair of eyes. Could be a friend or interested party. You could add an attribution "Edited by <name>" so they get something out of it perhaps.
It's pretty common amongst webnovels, translations, and fanfiction for an editor to help out and get attributed.
Having an editor would definitely help! Good idea to think about. Just not sure if a free blog is worth investing that money.