CapnZapp
Legend
I am not sure what problem you see.Then you're going to end up with the "Big Six" problem again.
There are items in 5e (like in 3e) that are obviously better than others, even if you set the prices far more narrowly (like 3e/4e did). As long as you have items that directly impact "the numbers" (AC, HP, Attack, Damage), they will always be far more valuable than items of limited or situation value (like Potions of Longevity or a Wand of Secret Door Detection).
If you were interested in comparing the cost of say, a cloak of protection to a cloak of elvenkind, my gut reaction is to price the cloak of protection way above the cloak of elvenkind (say, 5,000 gp for the CoE, but 50,000 for the CoP). There is no way I'd price an item like Gauntlets of Ogre Power for less than a million GP.
Could it be that you think I want any price list to conform to the rarity pricing bands given by the DMG? Then I could make some sense out of you concerns. But why would you think I want to be beholden to that half-arsed 5-minute job of a solution?
You present a problem but you're already onto the true solution.
There will be no "big six" problem if the different abilities are priced well. Precisely as you say yourself, completely ignore the rarity ratings and set your prices according to the real utility of your items. While a million GP is perhaps a tad prohibitive

Or rather, I am sure there will be ways to squeeze the most out of ANY price list. But that's not a good reason to not even try.
Especially since everyone involved (players, DMs, designers) have access to over a decade of real play experience and data.
Not only do I expect WotC to set their prices in a way that accounts for the Big Six problem... I expect them to do better in most if not all regards than the 3E designers did back in, what, 2002? with almost no data or play experience at all*.
*) I know there was this thing called AD&D.... but d20 was a fundamentally different system (much more different from AD&D than 5E is different from 3E)... and since then this little thing called the internet have vastly increased the intelligence available to game designers... so, yes, I believe I have good reason to be hopeful
