The only thing with this is that it defeats the official purpose of remakes. But then again, I don't mind that at all either. They need to start milking their creations rather than rely on silly downloads
Countdown to pokemon X & Y and PS4. Burn Black and White.
The price is really hard to guage and short of self imposed or good design, it would feature no challenge.
On top of that, let's get this out of the way. Remakes with every pokemon available have no real appeal. Limited catch set that is dated and, in most cases, short of expectation by this point until a forced post game may invest in them.
HG and SS showed one thing. Remakes with nothing to contribute have nothing to contribute.
One edge for DLC, though, is that it's got to be sequelish. They can throw in new twists to try and make it comparable to the new game. But even then your changes are few and spread out.