That other advert appears to be a polish built one too, the markings on the scope look to be from polish factories and manuals look to be in polish not russian.
They are hard to put a price on really. Russian ones get more of a premium though. I've got the russian made 1pn34 scope which is the slightly later model but still gen 1. You can get polish made ppn-3 scopes from polish marketplaces in good working condition for around £200-300 depending on postage to UK. But thats from a country where they aren't as rare so bare that in mind.