This is a modified version of Teambets (also modified by a member of these forums, but not to this degree) which has been changed to use a pot-based system (to avoid injecting large amounts of gold into a server's economy) although I have removed several of the features, I'd be happy to re-add them if people would actually use them.

sm_goldbet_enable
sm_goldbet_maximum Which controls the maximum amount a player can bet, defaulting to 40
sm_goldbet_minimum Controls the minimum amount a player can bet, defaulting to 5
sm_goldbet_betratio Defines the amount you can win per gold you bet

Update: Fixed the translation issue as well as a minor bug (due to some issues with integer math, sometimes it would award no gold, even if you won)

Also, due to this plugin's simplicity and usefulness I wouldn't mind if this was one of the packaged addons (especially after I add my last addition, less requests).

Commited, as well as updated to add two more cvars, fix it so that rebetting is impossible and a few other small improvements.

Committed with TF2 support.

Addendum: Translations will be broken by this, you need to change "Invalid_Team_for_Bet" to "Invalid_Team_for_Bet_CSS" and "Invalid_Team_for_Bet_TF2".