Yes I agree, I would also be willing to pay. Even if you only added 3 things, the most important is seeing Lisa close that bathroom door. The reason is that it is an important moment where the antagonist actually SEES the player, you make first contact right up front in their face. This instantly puts you on edge because you know it knows you are there. This makes the next time you see Lisa way scarier and every time after that as well. If you could add the roaches, and the missing sounds like hearing her footsteps when she walks towards the bathroom when you are trapped, that would be amazing.
Absolutely, the short glimpse is the introduction of Lisa, it creates much of the tension of the whole game. Roaches would be great (Laczowskis remake, here on itch.io too, has them) and footsteps would be great, but Lisas appearence is the most important in my opinion.