Is it ok to set up a bounty for a question, where I already know which answer I want to accept?

Question

The reason for setting up a bounty is, that I want to reward a similar but later answer, which goes into great details, but in the end is very similar to the earlier answer, which contained everything I needed.

I want to accept the earlier answer, which incidentally is the one with the highest amount of upvotes, and reward the second answer with the bounty, because the user goes into great details and adds additional very useful information for me. I want to reward this additional information. But I think the prior answer should be accepted, because it came first and was already sufficiently satisfactory at least compared to the later answer.

The relevant question can be found here, the first answer, the second answer.

Answer 1

Yes, this is one of the intended usecases for bounties

If you click on the "start a bounty" button you will first be asked for the amount of reputation - something between 50 and 500. In case you want to award multiple answers on the same question with an additional bounty you have to be aware that you can only offer bounties that are higher than prior bounties you awareded on the same question with the exception of 500 reputation. See Can I split a bounty? for more information.

After clicking on "Next" you will get a list of all the available standard reasons that bounties are supposed to be used for:

• Authoritative reference needed - in case you would prefer answers with more/better citations for example
• Canonical answer required - if you think it's an extremely valuable question for a very, very wide range of people and you would like to provide a very good standard answer for all the people coming to this site to find exactly that
• Current answers are outdated - in case something changed and you would like to see an answer that addresses the present day version of the problem stated
• Draw attention - there are no or not enough good answers yet
• Improve details - there are answers, but they are not good enough yet
• Reward existing answer - exactly what you are asking for; this reason could mean that there is one answer that is spectacular and you want to accept it and think the time the user put into it is worth an additional amount of reputation or there are multiple very good answers that deserve more than upvotes and some more recognition by staying in the active list for some more time

If you click "Next" again you can also add a custom message if you want. You could for example write your reasoning there or link to this Meta discussion. Be aware that bounty messages don't support the full range of markdown, so they might look a bit weird if you expect highlighted links or emphasis. See What markdown formatting features are available for Bounty remarks? for more information.

For a list of details about the bounty system see also the official FAQ on Meta.StackExchange: How does the bounty system work? and the privilege page for setting bounties (75 rep).