My reputation is 76 and therefore I'm eligible for setting bounties, I can set a bounty for eligible questions and even on my own previous eligible questions, but when I want to set a bounty on my own question that I've given an answer myself (which is incomplete and I'm looking for other answers), instead of seeing "start a bounty", I see "question eligible for bounty since 6 hours ago". Clicking on that gets me to the help page. I thought that's because I've given an answer myself (which is fairly logical, but not written in the help page). Therefore, I tried copying my answer to the question details and deleting my answer, but after doing so, nothing changed and I still couldn't set a bounty. I thought maybe that's because I can still see my deleted answer! So I undeleted my answer and made it Community Wiki(!!!) thinking that doing so might help. Even after that, I can't set a bounty!!
From the help center:
To avoid overly promotional bounties, if you are offering a bounty on a question that you have already posted an answer to, your minimum spend is 100 reputation (not 50).