Ballin' out of control at a sample sale is too easy. The deals are substantially better than retail and regular sale prices, so prices can be hard to pass up. Having multiple credit cards on hand will be all of the convincing you'll need to buy everything at the sale. A good way to avoid overspending is to carry cash on you. After budgeting for the sale you'll be attending, visit the ATM to withdraw the amount of money you plan on spending. Carrying cash will curb your spending and really makes you think about a purchase. Also, cash sales mean you're in a good spot to haggle a deal.
Bring cash money.