I’ve been thinking about buying some gold border cards for premodern. Things like Wasteland, City of Traitors, and FoW are a fraction of their cost as gold border cards.

I’m wondering for your typical unsanctioned vintage event, would gold border cards count toward the proxy limit?

They’re real cards after all.

they're real cards in the same sense that CE/IE are real cards. i'd expect events to at most put them in the same bin, and possibly worse as the front looks different.

the particular cards you mentioned:
wasteland is the kind of card you should just own, they're $20 a card for real ones, you're not saving as much on them as you are on City and they're much less niche. Fow also looks to be $20-30 for gold border copies, at which point for your set of proxies you could get one real one and play with 3 sharpie proxies.