nice thought!
However, i dont think it would ruin the economy of the game. Since I personally think it works very well, the only ones that will suffer from this are the people making huge profits by charging way too much for some items. Eventually, there will always be a certain demand and supply for items, deciding on what the price will be.
In my linkshell, we often ask each other what the price differences are. I once shouted in Sandoria that brass flower pots were about 1k in Bastok in a shop, while they sold for 2k in sandoria at the AH. Result: in 1 week, the price went from 2100 to 1400. Somehow, it is back up again, so i think the people importing those flower pots were tired of big effort, for the small trouble.