I do know there was already a suggestion for this from DIamondHogger123 but this one is improved.

The idea is so a player can type /cf it pulls up something that say create cf you click it in the chat is say
/cf create $00. then you type /cf create $500 the lowest you can do is $50 once you create a cf anyone on the server can do /cf show it would bring up in the chat all the coin flips players created Example:

sam_drums: $50
jojo_ted: $120

then you type /cf accept sam_drums after they accept the person who made the cf would get a gold nuget. then something in the chat comes in and say $50 have beed taken away from you then it both players get teleported to a room and who ever creates the cf has the gold nuget and throws it in the middle of a water current flowing left and right and which ever side the gold nuget goes to wins. The gold nugot will be unsellible