Tools
You can get dollar store tools if you are desperate and in a bind. However, you will get more out of these pieces of equipment if you get more expensive ones. Those will last years and won’t break down soon.
Batteries
It is a good idea to avoid batteries from the dollar store. After all, they are not made with the same standards and probably use older formulations. There is also a possibility that they will leak on you. When we talk about batteries, brand names are much better than cheap ones.