Okay, in Far Horizons, a business owner(s) can buy a security upgrade package for their establishment - better walls, security cameras, better locks and so on for 10K each. One of the upgrades is getting a security droid.
. .. but why not just buy security droid? It's cheaper (page 412 of the main rules says that it runs 9,600 credits) and it seems silly to tie up one of the three business upgrade slots for something you can just go down to Joe's Used Droid Lot and pick up.
Is there something I'm missing here?