The emperors cost about $80.00 (for the 400 gph model) retail, but you
can order them from catalogs for $50.00 here in the US. I get them from
a friend of mine who manages a pet shop for ~ $35.00 (he gets a nice
discount, which also shows the markup on these things). I switched to
these from cannister filters because those damn cannisters are a pain in
the butt. Yours sounds like a neat trick, but I don't have time because
of full time school and work. Between that and my fish, I hardly even
have time for my wife!
Jim