Get the new phone. At least you'll be getting a new warranty.

When my old cordless phone died (after 10+ year), I bought a refurbished
Uniden system, which did not please me. I took it back and go a GE DECT 6.0
2-8871 system. Not only is everything well-laid out and generally easy to
use, but the base station works even when the AC goes off. That is, the
basic phone operation is available, powered by the phone line when AC isn't
available. That's nice.