Based on the info in the Blue Book, Korriphila pistols are first rate. It says they only produce about 30 or less pistols per year. They don't list the model you stated, but if it is of the quality of the ones they do list, it is worth several thousands of $$.
See if he will take $1,000. You should stand to make some profit off of it if you don't keep it yourself.
".. manufactured by Intertex, located in Eislingen, Germany. ... imported by Korriphila, Inc. in Pineville, NC."
[Added]
After reading JohnKSa's post ( he was posting as I was posting), forget what I said. I looked up the Budischowsky TP-70. Looks like it is worth a max of $440 in LN condition; probably closer to $350.