The solution is to set your limit pretty high (100 times your average or so) or, alternatively, have shorter limit intervals - 100 times your daily bill is stil

The solution is to set your limit pretty high (100 times your average or so) or, alternatively, have shorter limit intervals - 100 times your daily bill is still a lot less harmful than 100 times your monthly bill. The only 'real' solution is proper alerting, but even then it's pretty easy to rack up a bill of several thousand dollar before anyone realizes what's going on.