Yeah, $150 is a small prize fund, considering that it is distributed among 300 participants. However, you should also keep in mind that the Funfury competition is held every 12 hours, which means that Betfury spends $300 every day or $9k every month for this competition. In that case, I wouldn't say it's an insignificant amount, and it means that the Betfury team should keep track of the abusers' activity anyway.
The amount all adds up but don't forget that they give out the prizes in a combination of USDT and BFG tokens (I think the ratio is like 30/70 USDT/BFG). Personally, I always like to win some extra BFG tokens as it means more daily dividend for me!
They are also spending millions of BFG tokens on partnership which means the reward on there tournament is just small considering the way they spend there tokens on different marketing promotion. The token value is also very volatile since it was being use as reward tokens on all of Betfury tournaments, giveaways and promotion which makes the token value is not that reliable on determining the total reward value.
The devs has a lot of reserve BFG tokens for marketing and promotion which means the price will not gonna grow much in long term.