Unfortunately it is 2-3X the cost of solid/riser cable. Cat5E plenum 1000 Feet is about $200, CAT6 plenum is about $300. Usually you can do a small office with one box (maybe 2 if you take our advice to always do more drops than you need). The key is to be smart about the patch panel location. You want to put it in the place where there are the most devices.