Being sent slabs without bags would be a little annoying, as, to begin with, they could get scratched or scuffed while being stored with the dealer. If buying slabs, there's a clear indication that the client is condition-conscious to some degree, and it would be common sense and courtesy, when distance-selling, to bag and board the raws in order to minimise the risk of spine bending, creasing or dings while in transit. The raw, regardless of its price or what the market is currently saying about it, might have some special significance to the collector, even if the seller believes it's total drek.