We use to play a lotto as well, where everyone who wants to play kicks the same amount of gold into a pot, then everyone gets one roll. You decide at the beginnng if it's winner takes all, or if the pot gets split among more winners (50% of the entire pot; 25%; 15% & 10% if splitting the pot with 4 winners for example).
First all the Gold is collected up front. "If you can't pay, then you can't play." There is never any risk of getting kicked from the Guild for playing a lotto.