I think you can find better condition at 150. If you look at the classifieds here and airgun warriors etc you'll find D34s without rust or screwdriver damage at that price range. I personally own the RWS 3400 Acapulco mentioned and would not recommend it. It does not have an adjustable two stage trigger (like a Diana does), and in fact has quite a heavy trigger. It has a nice stock but is a frankstein of parts mostly from Walther and it means dealing with Umarex if things ever go wrong and Umarex is not exactly known for positive customer service experiences. Third party support is around to some extent for Walthers but alot less than it is for a D34.If your friend is after a D34, I'd stick with that and keep browsing.
I picked up a refurb .22 RWS 34 T06 on sale from Pyramyd in the last year with no mount or scope. I thought I got a great deal on it and it cost more than the one you're looking at. I can't fault its performance- it has a great trigger, fine accuracy, and makes over 700 fps with midweight pellets. Mine is not date stamped and I think it is newer than 2018.My only concern would be that the 2018 model might fall into the timeframe when the T06s were shipped with molding artifacts on one of the trigger parts, and they have excessive 2nd stage creep unless that part is stoned flat or replaced. And you're right about the modern RWS scopes being junk- the one that came on my Pro Compact rotated the reticle within several hundred pellets.Overall I think the $150 gun is probably a good deal if it doesn't have any hidden unrepairable flaws like a bad barrel or something. Airguns aren't getting any cheaper these days.