My piece of advise would be for you to not take money that you don't want to spend out with you - because if your as bad as me, spending money after a few drinks, you WILL spend it - regardless...
I spent about £450 (a big chunk of my budget for the week) at Space on the Sunday then carrying on for a bit at DC10 ( I think!?! - its all a bit hazy! ) then we went to Bora Bora for a bit before getting a taxi back to San Antonio - fair enogh, it was a top day/night but it was mostly on drink!!!
I didn't realise I'd spent so much until back at the hotel where my girlfriend proceded to go completly nuts!!! I was ok though as I had my credit cards with me (for emergencies).
If I didn't, I would have been totally screwed for the rest of the week as we only arrived on the Saturday...
Mark