Putting together a 5.7 AR and would like a nice lower for it but not really wanting to drop $400 at retail. Anyone have a decent AR lower for sale? Love the Spike's lowers, but have to avoid putting so much $$ into a AR-57 that won't support a lot of resale value down the road. Will probably take a trip to Bill Springfield for trigger work anyway. Swapping uppers/lowers is ok, but awkward with an upper sitting in the safe therefore the search for a decent lower Also have an upper with a permanent carry handle that could be traded. Thanks.