I'd personally be folding here because I'd rather finish ITM than on the bubble.
If I'm playing to finish ITM and then aim for first, I'd be folding - and I'd be watching the tournament lobby and using my timebank if available to see if enough players go out so I'm guaranteed to finish ITM with a push anyway.
If my mind in that situation was "I'm not that far from being in the money, should I fold?" I'd follow my gut feeling and not push. You were waiting for 50/4050 or 1 in 90 players to go out.
Not played on pokerstars for a while, but if it's 9-seated tables then you'd only need one player for every ten tables to go out in approx 1.5-2.5 orbits. I'd see no problem thinking for a long time about each hand and then folding here.
I don't think there is a "correct decision". Some play for 1st, others for finishing at least ITM. Against 99 it was a coinflip situation and unless the table was shorthanded I don't think I'd have been calling with 99 with so many people to act after me.
When I'm shortstacked and on the bubble in MTTs I take my chances of being able to fold to the money and my risk aversion into account. If the lowest payout means nothing to me, I'll get my chips in on a possible coinflip. If the lowest payout is meaningful (e.g. if the buy-in was low compared to it) I'm likely folding every hand not caring if it means my last hand is my ante or blind putting me all-in.