Few Shops Questions(Trigger Related)

1- How do we set prices of items through triggers?

2- Are there any way to recognize how many items of a type a shop has in stock?
Or could you give me a way to make a building sell 2 items of the same type in 2 different slots(keep in mind that the items will be added through triggers)
I don't want to clone every item with different button position, I want a Generic way to do it

Setting the price of items via triggers is not possible at all =\. now the second question, you can use the trigger - Neutral: Marketplace create item, I am not totally sure if any of that helps, but I hope it does, and to change price of an item, just use the Object Editor and go to the Items tab.

The only way I can think of is set all of the item prices to 0 in the object editor and then have a dialog box pop up when they select an item telling them the specs and price and everything with a yes or no if they want to buy it.