Couple of things to point out: It MAY BE that SOME of the refurb models are actually brand new. Whenever Apple comes out with new stuff, they put the older models on the refurb store. (Source: MacRumors threads over the years)
Another thing to note is that these refurbs are limited stock, so if you want one, order fast.
Another point: Consider the base level 21-inch model too. Those start at $1199, and have the same processor, RAM, screen real estate...And in this scenario, you're buying a NEW computer (since what I said above is not always true, or maybe completely false altogether).