I don't believe it's discontinued. There were a number of them on sale for $299 from a DEMA deal, if you can find one of those, that's the best deal I've heard of. They are made by Pelagic, and are very similar in workings to my Aeris Atmos Pro. I really like them. I haven't looked at the batteries, but my Atmos Pro uses batteries that are available at Wal mart and Radio Shack for a few dollars, as opposed to paying $14 for them at the LDS. You won't have a new O ring, but you don't need one. When the batteries crap out, they do it very abruptly. Mine have done so twice, once on the dock at Cozumel (I ran to a dive shop and bought more) and once on a boat in the middle of Lake Michigan (I had extras this time). I have also loaned or sold or given batteries to others whose batteries abruptly went off.
So I do recommend that Aeris and I do recommend carrying extra batteries.
Dave