Tools
Do you need to use tools but are away from home? If this is the case, you can go to the dollar store and pick up cheap ones. However, you should have a good set at home. They are worth the extra money!
Batteries
The batteries available at the dollar store normally run out of juice quickly since they are not top quality. One explanation for this is that they do not have modern formulations. They might even leak! When it comes to picking out batteries, it is safer to simply stick to your favorite brand names.