As a frame of reference, sometimes my players are able to purchase restricted (and maybe forbidden) items from someone who is legally acquiring them. Obviously there's typically a markup, but I was wondering whether all the gear listings are the "black market" cost of the items? Or are they the base legal cost (in which case i should mark up over what is already listed)?
I always presumed any gear was bought as quietly and safely as possible, then cleaned up.
So the base price is the base for normal gear retail value, after some RFID tags removed.
Anything with an R is probably bought from an overstock vendor that is willing to not check too hard on the license, so that the ballistic data is linked to basically nothing.
Anything F though is probably either stolen or sold by some government agent tweaking the papers and exporting to the black market for kickbacks and the 'retail' price should be presumed to be black market.
The book though kinda presumes that basic items are hard to trace, so if the players ask for anything more or less legit, I'd modify costs from that base assumption. I'd never automatically assume they tried to buy F items 'legit' because that would be pretty much impossible, or tried to buy second hand pre-owned 'only involved in 1 murder!' R items unless they asked. Or had no choice, but I'd let them know ahead of time.