If you do not want to take a risk then you can start the bounty. There is no risk here only you will have to work on time and you will get your payment at the end of the job.
You are mistaken if you think there is no risk involved with bounties. At least half the bounties turn out to be a disappointment. Either they don't pay at all, or the tokens are depreciated so much that you are being paid peanuts. So I think there is a risk involved, but you are not risking your money, you are risking your time, which is sometimes worse than risking money.