The solution is obvious: Don't remake Diablo II.
Seriously, the only thing they put any effort into at all was the skill setup (and the FMVs). And, granted, the result is awesome, and a much more enjoyable way to play.
Had they put that sort of effort into making the rest of the game evolve similarly, we wouldn't be in this mess.
And, frankly, I don't care about the game economy at all. I would prefer to be able to play the way I want, independent of market fluctuations or number of players (and, seriously, try getting anything off the AH once the initial rush dies down). I think the reliance on the economy simply hurts the gameplay in the long run, and, frankly, I think this was obvious even taking a cursory look at Diablo II, and I don't think Blizz has done anything to fix it. The AH certainly isn't a way. It doesn't put any limitations or controls on the economy, it just makes sure that Blizz gets a cut of all the transactions.