It's on the high side, but...honestly not absurd? "Party" implies one night rager, but the source says "in-person company event." That seems more like a multi-day company onsite to me, and the total bill per person there probably includes travel, accommodations, food on top of any overall event costs.

Bringing a remote employee to SF just to work out of an office for a few days can easily cost a few grand.

I've been to all hands where it probably cost that much just in travel: business class LHR to SFO, hotel for a few nights, dinners, drinks, entertainment, venue, guest speakers, and on and on.

It doesn't seem excessive, the networking in these things is often really worth it

At the cited $340000 salary, it amounts to around the same as one extra week of vacation for everyone.

Seems plausible. Travel (some international), hotels, taxis, venues, food, and entertainment. It adds up. Probably not a single day event.

For an event where many employees have to be flown in and stay at hotels in an expensive city? That's normal.

Hosting in-person events for 10,000 people is expensive even without having to transport and house anyone.

That actually sounds pretty reasonable.