Like tile, most paint will differ slightly in each lot produced. If you plan to use the same color thoughout your house, it's a good idea to purchase as much paint as you can at one time. This will avoid any deviations in the paint color and save you an extra trip to the store.
If you are in danger of paying your mortgage late, send your payment via overnight mail. The cost of doing so is probably much less than your late payment. For example, a 5% late penalty on a $1,000 payment is $50. Sending the payment via Federal Express will cost you less than $15.