For me it would just be impossible to win it on the site I play (Crypto-Games), I don't wager nearly enough to even get into the top 5 spots.
I don't mind that they have a wagering competition though, there are other ways to get some extra winnings.
It is not only this site but most of the sites wagering requirements are not so easy to meet because those these sites want to make money. But it is just my observation if you look the investor's profit from crypto-games site for last few months or even more. They are always making a profit and that means always gamblers are losing money on that site. So I don't think it is good to wager in this site for winning some money and risking more money.