Artem, you should make it a double elimination (and consequently, a best-of-3 in the final), otherwise there's a chance of being eliminated without a chance to compete for first place after just one loss against a top player. And immediately, there's a high chance that players of average skill simply won't participate in a tournament where they don't see a chance of winning a prize (from their point of view). As a result, the very group of players who would have given up and gone to drink, but who contributed money to the prize pool and the payment for the conference room, simply won't come, and everything will be paid for by 5 people who plan to dominate the CIS region.
Well, it's a matter of personal preference, but for me, participating in the CIS region is a matter of prestige.
If you're going to give up and go drinking, it's better not to participate at all.
Better less, but better.