I had a similar worn PF that I sold to a friend for $1500. I added a new CPR plastic set and a new PF protector plus all the stuff I usually do, posts, rubber, flipper bats, pop caps, etc. New tube and a bit better cab, plus LED's in the inserts and head. He's routing it now so I musta done ok.
Having new boards is nice (and spendy) but does it really add value to make something do what it's already supposed to do? It's not an upgrade with the door shut, it's a side-grade...JMHO...