I guess the seller posted it at 20k and got inundated with messages so now they're "entertaining offers greater than the ask" or some such. At any rate 20k does seem like a good deal...
https://www.facebook.com/marketplace/item/880526647415723/

That 912 looks like it still needs some work....
I have a friend putting a 4.0 Rover into the back of a 912 ...he bought the car when he was 12 :)
Ugh. I had an awesome semi-retired co-worker with one of these back in 2011-12ish. He'd drive it to work every nice day. I expressed interest and he told me he'd sell it to me for $6000. Still kicking myself for not buying it.