No idea that even cat healthcare is just as expensive als human healthcare… weird. But isnt there some shelter or org that does check ups for ppl that dont have a shit load of money? I think i read that somewhere some time ago. Here for example u can het free Neutering or sterilization once or twice a year from shelters and vets even. But on set dates. But that doesnt help you since im on the orher end of the world :)
Anyway. Mine does this dry heave and sometimes with some clear fluid and grass and been doing that for 10 years. Onone knows why my vet said, sometimes some cats doe this. Not really an answer but still i dont think you need to worry unless she stops eating and stuff…but not a vet :)