does apple buy back macbooks?

The don't buy used equipment. The closest they come is giving you credit for recycling.

you are better off selling it locally or on eBay.

Check out the Apple recycling program > Apple Recycling Program

You might also want to check out Best Buy if you are looking to upgrade your computer. They have a trade in program if you are looking to get a new computer where you can get something off your old computer. But as others have said, if you want to sell it, the best place is E-bay.