There are many places that sell reconditioned tools, and the best place is always from the manufacturer. A manufacturer has people trained in fixing the tools and will use industry parts, but you will likely end up paying more for the reconditioned tool than if you get it from somewhere else. These will also usually come with a limited warranty.
The next best place is a certified re-seller of reconditioned tools. These people have been certified to repair the tools and sell them at a discount. Also, resellers are often local versus buying over the Internet, so you can visit the store if you have any problems.
You can also buy reconditioned tools at various tool websites, flea markets and even garage sales. You will not be able to verify if it was quality work or if the parts used were industry standard or even reconditioned themselves. These often do not come with a warranty, and you may have no way to contact the seller if something goes wrong.