Yeah, I saw that. Not exactly consumer prices are they?

Reading the forums there are some dual LAN Atom based mini PCs that seem OK.

Edit: Also http://store.netgate.com/Desktop-Systems-C83.aspx has some preconfigured options at under $300.

Those are the same things.

If you do not want to financially support pfSense, you can buy hardware from Netgate directly, starting from $299. Even cheaper as a kit or with older hardware, but you decide for yourself whether it will be adequate for you. I'm planning on buying an assembled APU from Netgate for myself; right now I'm using m0n0wall on a separate P3 PC (Celeron 1000), modded for silence. Probably will try out pfSense beforehand, on a separate CF card I just ordered.

The Netgate APU2/APU4 devices don't appear to be available directly from pfsense. They do say money from them goes to pfsense though (and they advertise them on the pfsense site)

OpenWRT on a Buffalo WZR-HP-AG300H is a another very nice and cheap solution.