Well Rosie dear... then you want something with pizzazz I suspect that will require a volunteer programmer...
One alternative is to use one of the many available "shopping cart" free and open source software like the popular ZenCart to sell items online (for instance, this shop). Zen Cart doesn't have the most intuitive backoffice, in spite of its widespread use. Also, to make land sales happen "automatically" (I don't think that this would be needed, though) it would mean dealing with the complexities of having a bot to mark the land for sale for an individual, etc.
Apparently there exists software specific for listing "real estate" offers: http://www.open-realty.org/. It seems to have 6 years of development and continues to be very active. One recent example of how it can work is http://www.georgiahomesdirectory.com/. It looks great, but of course I have no idea how "easy" this is to install and keep up to date. Does anyone have some experience with this? Note that there seem to be a lot of free and open source solutions out there — just search on Google for them, I found half a dozen! — so I wonder if anyone has tried them out and could give some feedback...
Of course, if you wish, I'd be happy to install one of those and let you have a go at it just to see if it does what you have in mind...