Can it circumvent and avoid awarding bounty for own answers and reward answers by posters other than the author of the question. Why avoid the author from starting bounty itself all together. In such case, won't the author be eligible to start bounty to draw attention, while having no interested to gain bounty which was offered by himself. this rule looks a bit redundant and avoidable.
I had answered it just to show progress and no intention of gaining points.
You can find links to some basic information about bounties in the corresponding tag-info.
These two points from the faq item How does the bounty system work? are relevant:
You must have at least 75 reputation to start a bounty, and at least as much reputation as the bounty amount.
and
If you have already answered the question before, the minimum bounty offer is 100.
So you cannot offer a bounty simply because your reputation (at the moment) is lower than minimum possible bounty amount. Once you gain enough reputation, you should be able to offer bounty for this question.
It seems that this feature was implemented in 2011, see: Clever bounty reputation hack and 2011-09-20 entry in Recent feature changes to Stack Exchange.
I will mention that deleting your answers will not help in this regard: Why can't I add a bounty worth 50 reputation after deleting my answer on a question?.
