Everyone knows that mudflation occurs because there is an unlimited source of material wealth (coin and loot) and the rate this is added to the economy outpaces the rate it leaves the economy. This means more wealth is in everyone's pockets leading to inflation and exponential rate of devaluation of items.
Here is an idea: When Protf creates their economy system, include the ability to inflate merchant/vendor/etc prices universally. Add a simple scale factor so dev's could go in and adjust the prices merchants are using. Now, this could be automated by tying it into a "drop counter" which keeps track of how much coin and loot is added to the game. If the player base starts really moving along briskly and lots more wealth is getting into players hands, the NPC's should ALL raise their prices. This would slow down mudflations, seem a little more realistic and help items retain their relative value.
Not a bad idea all around but how would you handle prices for new players a few years into the game?
Another thing to keep in mind is that in most games in my experience you buy very few things from an NPC vendor the higher level you get so this may not have the same effect as intended long term.
The problem will be newbie areas. I do think prices should be revaluated from time to time. What we really need are more/higher priced consumables for higher level characters. Inflate the prices closer to High level fighting zones.
I could imagine having to pay a "toll" to enter certain areas also.