The thing is that $50 per book is a heck of a sticker shock, and it's going to dissuade a lot of sales from people who might be able to afford the book -- but because WotC decided to kill 4e early, and haven't been selling anything in the interim, these players have probably found something else to play. Hmm, $50 for a book from their FLGS... or $50 on miniatures or map packs or an adventure path for a game they're already playing?
D&D has name recognition, but it's also a new product. And WotC has to take that into account. If you don't like the system -- and around here, PLENTY of people absolutely HATED the playtest -- then you're already disinclined to pick up the books. $50/book pretty much seals the deal. End result: People walk away from D&D.
And yes, there are a lot of people out here who can't afford $50 a book. I, personally, am on social security -- I receive $725 a month, and I can still afford the books on the release schedule they've set. But there are people in much worse boats than the one I am afloat in. D&D has always been a form of entertainment which the economically disadvantaged person can enjoy, up until now.
Well, if $50 is too expensive, free is much better -- people are going to resort to thievery to get this product. I expect to see cases of outright theft, people walking into a store, putting the book under their coat and walking out. It already happens with Pathfinder books at the local Barnes & Noble. And at a $50 price tag, you're going to see it happen more often than you would for, say, $30.
Also, I expect full well that the entire system will be heavily pirated. DRM on PDFs can be broken, sometimes just by using a (pirated) copy of Adobe Acrobat to resave the entire file without watermarks or password protection. And if you don't have a tablet? Then you print pages at the library.
Or people will just ignore the new product and keep playing with the system they already have and enjoy.
Either way, WotC is losing sales due to the price tag.