I'd say the thing that strikes me about those Legacy server prices is that they're directly correlated with the fact that the hacked RMT gil that was adjusted on other servers was never touched on Legacy servers (remember that whole gil > x amount = ban fiasco?). The problem is, if you're on a Legacy server, like Sargatanas, for me, and never took part in any of that, you can't even see that kind of money in your dreams. Sure, the very richest of the rich have that money, but not only do the rest of the server not have that kind of cash, there simply isn't any way given current in-game gil generation to even create that amount. Selling to the rich doesn't work either, as their excess gil will disappear into that ginormous housing price.

TL;DR: If you're on a Legacy server and didn't participate in the whole selling 2*s to RMTers debacle a while back, you're out of luck.