Estibot gives these names(especially mexican.in)high appraisals because of the strength of the keyword. As you can see from their related sales section on mexican.in, the keyword "mexican" has been involved in several low to mid $x,xxx sales.
But estibot's appraisal is ultimately flawed because most of the "mexican"sales are in .com or .com.mx, not extensions like .IN.
Also, we can easily assume estibot's appraisal is off because we dont have any historical sales of these sort of domains in .IN to compare and reference.
mexican.in and plano.in are probably actualyl worth mid $xxx if a buyer is found.