dont buy unless it has a chinote title deed paper or nor sor sam , if the land has no papers then you allready know the answer to that. rice paddy land per rai in kalasin / isaan is around ( my wife tells me ) 100 - 150 k near main road, then again wife could be wrong.

It all depends on where the land is in Issan. Some land in Loei is about 25% cheaper than in Nong Bua Lamphu.

"but when they say they can get 50,000 baht more from someone else"

Standard lies when buying land here there is "always" someone else who wants it so what you do is simple, tell them you dont want it, they will soon be on the phone saying no no no they really want you to have it they dont really like the other buyer etc etc all lies all part of the game.