But the example is one that will never happen, so it doesn't really work as an example.
I can understand your grief if you can't find any potions to buy, but I bet if you put a little effort into it, you could easily get some, and not buy on a "per need" basis, but stock up on them for when you do.
As I understand it, the reason the greater restore was removed wasn't purely for the removal of having an NPC that will cast a full heal, I think it was intending to make some ailments more or less permanent without PC intervention, to cause more consequence. I know if I got hit with a level drain and I didn't have a means of getting rid of it, I probably wouldn't go back to that place again until I did have a means of combating it, and that may be what you have to do.
For disease, expanded healing kits might be nice, but that's only an added detail, since the priestess will still cast remove disease.