Ned,
It's pretty much a 'generic' DT jig. I've seen them at MLCS, Hartville Hardware, Woodworkers Supply, Rocklers, even Harbor Freight. A lumber supplier that I used to patronize when I lived in California used to sell them, too.
I have one (from the CA supplier). I think I paid around $50 for it, maybe ten or twelve years ago. You'll need a 7/16" bushing for your router, and a 14° dovetail bit.
Even though I also have a Leigh D4 jig, and I also bought that used Porter Cable jig from Bill Hylton at Five Barns last Summer, I still pull out that old jig when I just need to do a couple 'quick' half blind dovetails for drawers, etc.
Set up is pretty quick with it. The cutting depth setting for the bit is the only critical part, and after you get it right, just cut a guage for that in some scrap and save it. That way, you can use it forever after to make subsequent setups quick and easy.
If the price is decent, I'd say go for it.
BTW, does it come with a manual/setup instructions? If not, I'll see if I still have/can find mine for you.