I was talking to a friend who works in a gunshop about this the other day. According to him, prices will not be going down and demand for rifles with FH, bayo lugs and the stock of your choice will likely drive prices for awhile.
On the other hand, he works in a gunshop not known for its reasonable prices. So...take it with a grain of salt.
What will come down are prices for Glock and other standard cap pistol mags. It'll be nice to buy a Glock mag for $25 again, but I think that demand for those, and others, may also keep prices inflated for awhile. Really, who among us isn't going to want 50 mags for a glock in preparation fo the time they eventually renew the ban?
I wonder if the 10 round mags will be onsale after the ban expires....heck, they'd still make great range mags.