Vanpry made a good point about it - you need to build it into the system that gold is going to leave the economy on a regular basis through normal use. I think you should be willing to revisit the economy as time goes on to make adjustments - reduce the amount of gold coming in or the rate at which things decay. A lot of games, once they have started, would rather just tack on gold sinks than revisit their economic system. People learn the ins and outs of the economy, and veteran players can generate a lot of gold quickly just by farming a few areas, and that becomes an issue, and the response by many teams is to just make another gold sink or two, although some will revisit areas. Blizzard does this with WOW and Diablo 3 - if they find areas that people find to be really easy farming, they will eventually deal with it.
When you are talking about the common player, you have to be careful as well. I was saying don't touch housing/mounts/ships with taxes/rent/gold sinks, because you don't want a game that starts taking away things from players if they don't play X amount of hours to raise X amount of gold, and you don't want people to have to feel like they have to play X amount of hours every week just to keep what they have already earned. A sandbox should be where people do what they feel like doing, especially if they are paying a subscription or some other monetary contribution. Putting them in situations where they have to do a certain amount of farming in a dungeon or grinding away at a craft every week is going to decrease player retention, especially if they have limited time, and it cuts down on those times in-game where they just hang out at places or with friends.
I think you have to go with what you and Vanpry and others said, keep the item destruction/loss constant. With a game like UO, introducing things that made item loss and item destruction almost impossible really changed the dynamics of the game and the economics. On the one hand, people could make uber suits and weapons and rest easy knowing they won't lose them. On the other hand, it created a situation where gold started piling up in player accounts and a certain amount of inflation crept in when it came to other areas. It also through off PvP to an extent, completely taking the risk out of PvP, but that's for another thread.