You should probably edit the template to change that sentence - it wont load the amount you have because of the multiple currency issue I said above. It got halbucks from the phrase for vCash you are using. Ignore the amount it says and try placing your bet anyway.
I was unaware they added vBCredits as an option - in any case it should say Custom so that vbcredits handles the multiple currency functionality. The "Currency Amount" setting is for applying effectively fees or bonuses if you set the event to charging or not respectively.