Here's a doozy :-O

I don't know if this is even possible, but if it were that would be groovey.

If a player has a certain unit I don't want him to be able to buy things from a specific shop. Now, he may have allied vision to a unit who can buy things from that shop. Is this possible?emote_confused

I think this can be done by adding a tech requirement to all the stuff sold at the shop. The player wont have the tech requirement whereas his allies will.