They aren't all that expensive, but where do you draw the line? Somebody who wants to put in a Kosmo, Goldpoint, etc. will want to buy the kit without the Alps to save money, then we get into some serious packing and inventory issues.
The supply of these controls is also not super consistent, fakes are abundant, there have been some dimensional changes that would be problematic for the long term supply of our kits. To get good units, it's about $17 per pot, and I wouldn't feel confident that we could order 100 at a time from any of our regular suppliers.