To avoid irregularities in the price negotiation of this account, can you let us know the amount that you are currently earnings on this account on either daily, weekly or monthly basis.
What you make in this game is dependent upon your play style. Personally I never tried to use it as a source of income, but I knew several people in game who were using it that way. My goal was having a little fun when I had free time and gaining skills and gear in the process. These can then be traded for real $. I always chose to keep my money in game for the most part and viewed it as a hobby. I'm a gambler by nature and pursued activities such as hunting and mining for the thrill of it. I could have taken my proceeds and put them into land deeds or some other stock like holdings and just sat there making a passive income, but that wasn't my style.
If one has the time and dedication needed to make an income from the game, it is surely possible.