Do not change that password

[Bill in NC]

Theft rarely takes place at the user's side of the computer.

It is far more profitable to target information stored on a company's servers.

Changing passwords every week doesn't protect you against hackers gaining access to Monoprice, for example, and stealing their stored information (name/address/credit card number/CVV).

Frankly, companies shouldn't be storing your credit card info in the first place (the transaction is either authorized or declined immediately), UNLESS you agree as a convenience to you.