The problem I see with trying to give value to in game currency is that you really can't. For example using the list of gear you show for an example, by around level 10 a single character is already wealthy enough to live comfortably for the rest of his life and ten more. I made a new character for this current test and reached level 20 today and I've already got almost 40,000 gil. By that, I could afford several suits of high end armor, all the food I could ever want, potions to drown myself in, etc.
So while it's fun to think about, it doesn't really work well in practice because players amass wealth far above and beyond what you would assume is the economic norm for non-players, and they tend to do it very quickly.
So while it's fun to think about, it doesn't really work well in practice because players amass wealth far above and beyond what you would assume is the economic norm for non-players, and they tend to do it very quickly.