Just sharing our simple Recipe Item Combination + Auto-buy mini GUI system we needed and made for our MOBA map if some find handy. (there may be better systems out there, I have not checked).
Features:
Item Combining (with Recipe): possessing all the needed items (referred to as Components in the trigger) combines them into a new one.
Auto-buy: if the buyer has enough gold for what's missing, he will buy the whole item in 1-click (instead of having to buy every component 1 by 1).
Important Notes:
Recipe items use Campaign category items, so reserve that category to avoid bugs.
Doesn't work without recipes. (easily changeable if you understand a little bit of GUI)
How to use guide:
Set Stats - Classification: to Campaign for Recipe Items.
4 variables need configuring itemComponent[], itemNumComponents, itemCompleted, itempriceTotal.
I'm not very active on hive so don't expect me to maintain it.