I will not say delusional sir, that would be rude
However, it is actually the cost prevents such things from happening, or in the case above, the Mig23/27 scenario
these modifications you mentioned, amounts to huge research, just like designing a new aircraft, and thats where the problem lies, testing and prototyping the whole damn thing from start to finish is expensive.
And there is always political mutuality between the countries involved, for example J7 - Srilanka - China, F16 - Indonesia - US.
These cheap deals did not just happen because they feel good at each other and decide to throw in some fighters to the party. Unless your country is on their radar and they need something beneficial from you, such offers are hard to come by.
Getting a cheap fighter procurement solution is not easy for cash strapped air force these days, its either swallow the budget cost and brave the politic storm, or none at all because you don't have any funds or political capital.
Another way to build up AF capabilities is to start from trainers, so you retain the training process and pilot skills, without having to invest in any certain fighter aircraft platform. Trainers are far cheaper to operate compared to full fledged fighters.
If you are looking for real cheap solutions, J-7 and JF-17 are the only real alternatives, but then you have to commit to Chinese parts and logistics.