how much you will pay for a page builder to resell unlimited ?
If you buy an extended license of an item you can use that one time in your selling product here in themeforest
If you need to include in another product buy another extended license
I mean if someone sale page builder unlimited license to sale outside themeforest. how much you can buy for this license?
It would depend on how effective it is, what its performance is like, the features it offers and so on – impossible to quite without more details
like goodlayer’s page builder or js composer ?
I agree with @Charlie4282
It is better to ask customers “Will you pay xxx$ for wp page builder?” with unlimited license and add features it have, than you will get good answers.