We seriously need a new shop/trading plugin.

[chinichi]

would it be possible to add a clientside addon.
not required to use the shop, but to merely simplyfy it.

If you ask i can provide the GUI for it.

Well that would require modding the actual files in the jar, wouldn't it? Or using some kind of mod-loader?
I can't see how you would make this easier than it is, though. You simply punch the chest that contains what you want, and then write "/adshop buy X" replacing X with the amount you want. Everything else is automatic.

Well i was thinking about Risugami's Modloader.

But if the user interface is that easy , then okay.