I suspect a number of the start collecting boxes will get a revamp as the change in edition has made some of them kind of meh. I don't see them changing the discounting though, the online "cheap" rules sets are all about getting new players in. The other big boxsets are not discounted at all, so I don't get why they do them.
Keep in mind that GW is pushing the new marines hard at the moment, so they will be "cheap" as they are a new army that GW wants to be on the tables and expect to see them getting some solid rules to back them up.