Rock5's StoreMultiBuy Mod, first version.
My mod based on BuffyS version 0.6 of Zilvermoons original addon.
http://addons1.mmosite.com/rom/content/2010-02-05/20100205180538833.shtml

I don't remember at the moment everything I modified. I no longer have a copy of the original addon and I can no longer find it online. The download link at the url above doesn't work. But I do remember that the original ony bought 1 item at a time even when buying stackable items. This version can buy stacks.