When is $50 not worth $50?

I have won $50 pit play at Ellis Island twice on the LVA casino. The first time, last June, the Ellis Island pit boss gave me 10 $5 chips that I had to play at least once through on any even money bet. If I won half of those bets, I would walk away with $50 (assuming no blackjacks if playing that game). The EV of this is just under $50 (since odds favor the house slightly).

Most recently, I claimed the same prize at Ellis Island, but this time the pit boss instructed me that I would be able to make one $50 bet on any even money game. If I won, I would leave with $50. If I lost, I would walk away with nothing. This makes the EV of the $50 bet just under $25.

Correct. If the first were play till you lose chips, or you were allowed to keep and cash after one play, they were worth close to face value, while a single bet is worth roughly 50% of face. EI apparently changed its policy, or one boss made one decision and another made the other, possibly without understanding the difference. Regardless, you're pretty much stuck with what you get in a situation like that unless it was spelled out in advance.

"Regardless, you're pretty much stuck with what you get in a situation like that unless it was spelled out in advance." ---- "Stuck with what you get"??? So in other words, the "boss" can make it up as they wish and what should be a good thing is now not as it should be. Is there a reason that the terms of this "win" could not be "spelled out in advance"? This type of behavior by casino personnel is what is glaringly wrong with Vegas - just make it up as you please, the customer be dammed.