Shift Clicking spells when buying only gives one
 

Titanium client, 7.0.801 server. PEQ database.

Goto a vendor with spells, Hold shift and buy the spell, you'll get one of the spells in your bag, but will be charged for the whole stack.

This only sems to apply to spells, as i have done it with food and wepons and such and it works fine.

I dunno if this is a db thing or a emu thing.