I'm looking for a phone or device that would block all incoming calls except from certain area codes. So far not much luck.

In event a scam caller originates from one of the white list area codes, I can always block it with my existing Panasonic.

Does such a device exist? If so anyone have experience with it?

What type of phone> Land Line, VOIP, cell ?

Land line, Verizon fios

I use the Digitone Call Blocker Plus .
It blocks well but a little complicated to program, straight blocking or white list of a calling number live is pretty easy.
I looked around a lot for a device prior to buying as I have an analog land line too and there is MUCH more available if you have a VOIP system.
I would ideally like to have one that the number is run through one of my computers (or built in) that programming and logging would be easier but have not found one yet for the LL.
So this is the best I can do for my archaic Land Line (ATT).
It does work.