Several states have similar laws already in effect. Basically law enforcement does not need FFL status to buy guns off the streeet and does not need FFL status to send surplus inventory to a distributor who then resells to FFLs who sell to you.
Often there is one "big" retailer who handles the sale of surplus guns, including the buy-back guns. It can take some hunting around to find them. Generally there are no real deals.
stay safe.