Looking at the refurbished section, the old 2011 one is offerd for $1,359.
I think that the new base 27" is a better deal.
For $440 you get New vs Refurbished, better CPU (2.9 vs 2.7), 8GB ram vs 4GM, GTX660M vs 6770. Most importatnly less glare on the screen. You'd also make at least 50% of the differnce when selling it. Personally, I don't see why anyone would buy the refurbished one (unless you need that DVD drive, and external won't do).
Speaking about the screen. I don't know how many here actually saw the difference, but after seeing both at the apple store today, the difference is massive. The old imac is no longer an option for me.