Hey, sorry for not informing you about this because I became inactive (even stopped my project for a long time) and my internet snapped a few days earlier. It just recovered today and I just saw your message.
So about your Stall, I have tried many ways I can and it couldn't seem to get right. The function in WC3 seems to sometimes work and most of the time won't work which is a bit frustrating to me
This function is the only function that can only make your spell work but in the end, it's crap..
So I guess in the end, your spell could not be done and I have to blame it on Warcraft 3 for not giving more functions or maybe my lack of knowledge in these. ><
Your Stall can still be made but not in the way that you want as in the players will not get to pick the item they want to choose to sell.
I'm sorry that I have to tell you this, my friend but I will try to keep on testing until I can get it right..
Unless I became frustrated again ><