The terms, amount, and length of the lease is negotiable. Moreover, your lease can also stipulate your right, but not your obligation, to buy the domain-name at some point in the future. As an investment vehicle, it becomes harder to estimate how much someone else would be willing to pay for an Internet domain-name. It is in the eyes of the beholder. Unlike a business address, for a name under this category its value depends on how much you are willing to give it up for, as it is impossible to determine how much someone else would be willing to pay for it.
Auctions are probably the best mechanism to sell such assets.
However, you should keep in mind that the market is still in its infancy. Thus, it is not surprising to see it currently composed mostly of sellers who have and are still acquiring domain-names as an investment instrument. We obviously believe that there is great value potential in this market for all parties involved. Meanwhile, to increase the visibility of our site and domain trading in general, we have started advertising, both print and online, in a few major cities. We are also in regular contact with some of the major business editors.