Warcraft 3 MODs

I need help editing the war3ft.cfg on how to edit so I can buy more than 2 items. Right now I can only buy 2 and and everytime I want to buy more it said need to replace another one. Some servers I played on has the optinion to buy more than 2 items so I guess it's possible.

How to buy more than 2 items on shopmenus? By default I can only buy 2 items at a time. If I want to buy 3 or more but I have to replace one. I try to edit the war3ft.cfg file but I can't find it.

Any help would be great ^^