Something pretty rare happened to me yesterday. Decided I wanted to get the 5000 sats I had in my wager bonus, and since 4RP bonus was still active I thought why not get a GT and rack up bonus points, but in the "safer" method than I normally do.
So 10000 rolls on 1 sat and simple martingale. And boom, busted within 1000 rolls. No need to say how much, lol.
Usually I manage to get several GTs just doing it this way for a couple of times or so. Now I must hunt my luck elsewhere for a while more.
Thats the point of betting here, it's player controlled and not place controlled, which means people usually bet on something they see guaranteed and get a lower return, but usually that means the other side has worse odds, like in a normal place one team gets 2.10 and here it gets 1.34 but then the other team gets 3.00 in other places but 5.00 here type of deal.
For this specific game it looks neither to be fair, so I agree with you, but freebitco.in doesn't decide on the odds, we all do based on how much we wager, and that should be the reason why you may not see odds that you like here, it may look like not worth taking the risk overall.