Most of the tournaments played have a top 40% player payout with nearly all receiving money back plus winnings. Placing higher in rank will typically increase how much you win.
When looking at the details for a tournament, check out the current/potential prize breakdowns. The potential prizes are what everyone gets if the tournament fills up, and the current prize breakdowns are what players would get if no one else joined. Please refer to this article for more information regarding prize pool distribution for current vs potential