Only the price of former "prebans" will really drop. Also, the former "postban" parts (uppers w/o bayo lugs, FS) and 'fixed' telestocks will drop.
There will be a RASH of purchasing when it expires, so you may actually see the price of AR parts go UP for a while until the demand subsides. I chose to buy my "preban" stuff now (to avoid the rush, and artificially inflated prices) and store them at a friend's house.