Whilst this would be a nice idea I don't think it's necessary.

Whilst a lot of people believe prices will be everywhere (and with the way our markets work right now, who's to blame them) I honestly doubt more than 10% of the current population will recall how much items were selling for before.
For example, Darksteel nugget +1 was about 130k last I bought it (about a month ago), I doubt that's how much it goes for now and I doubt that if I were taken away from the game for 4 months that I'll be able to recall that without having it written down.

If Darksteel nugget +1 is still going for 130k when 2.0 is live then I'll remove my shoelaces and serve myself some spaghetti.

I'd like to mention that I have said 4 months but this is just a number I've pulled out of my bum. Let's not make it the source of conversation.

The gil issue is only temporary and we'll thank Yoshida a year down the line for doing it.

All I really want in the market wards is for it to be fast and easy to check how much and items sells for and placing your own item up. At the moment it takes way too many clicks, moving around and time. No wonder people undercut like the Reaper.