You're not serious right?
If you are, then.... heavens, no. That would be a terrible idea.
First of all, you're making a power balance here. The richer gamers automatically win becuase they'll always have easier access to items poorer players couldn't afford and therefore would have to buckle down even more just to keep up.
Second of all, that devalues EVERYTHING in the game. Exotics lose any shred of value they had left, as would Raid gear. It would make Raiding itself obselete. And once that's done, what do you have left when you've got EVERYTHING from PVE?
Third, what makes you think Bungie wouldn't just screw us over and release the DLC at normal price anyway? I mean hey, "they paid for all this stupid shit. They would buy this no matter what the cost!"