At aquacave dot com the Octopus DDNW-250 is $599, granted that is rated for 650 gallons which I didn't look at before.
I am sort of a do-it-yourself kind of guy and the reading I have done says the longer the air bubbles have in contact with the water and the smaller the better. This has just been a few articles I have read from RC Mag, but it makes sense I guess. I notice all of these expensive skimmers only have about 12-24 inches of length. This one is 22. it wouldn't be but a couple dollars more to make a 3 or 4 footer.
So I was wondering if anyone had built one of the DIY skimmers and could compare. Even at $250 I will still lean towards trying it myself. More satisfaction that way, unless someone has tried it and they don't work. Should work though, the concept is fairly easy. Ryan is right though, changing airstones could be a hassle.
Any other opinions on the DIY?
P.S. The Octopus NW-110 is only $134, but is it any good? Rated to 90 Gallons?