See to us, we would be looking at logging IN/OUT traffic from an equipment library. Hidden tags, with a hand held scanner all linked to a working equipment management database. Therefore you can tell it is in or out (still leaves the requirement for staff input, but you cant have everything). This way the cost could be kept to a minimum.
I know what you are all thinking why not get the staff to register that they have taken an item and where it has gone. Thats what they would be doing but this is something that works along side, if the computer has'nt registered it being removed then the RFID will, along with a nice still of the culprit.
The other way is like they have in most fridges in hotels, the Led method, you remove it, it registers. (Found out the hard way when I removed everything from a fridge to put my beers in and ended up with everything on the bill. Just adds to your checkout time)