First of all, you need to be sure that it is a real heb. I can tell you if details are sent to me.
Then, you have to find out what is original, what not.
Then you need to find out what price is asked, what are you willing to pay.
I was offered once a basket case heb for 18 K . 10 years ago. Last one in that condition that was offered. I let it go as it was to much work. I regret it now. I was one day to late for a 10 K baske case also the same time. That was cheap but I need to say , the only heb part was the roof, rear scuttle and engine cover. Rest was karmann. The last driveble heb that was for sale is the french one.... It was more than 100 K. The last restored one was around 200 K.
I can say that I have tracked down all hebs the last 15 years... I have seen lot's come up for sale, and all of them are sold.
Maybe I can help you out iff needed. I know e few for sale now...not in advertise but mouth to mouth advertisement.... and only to a chosen few.
Greetings.
ZELENSIS, coachbuilt body from the 50's on a vw platform made in Belgium. Peter the heb detective