Thanks, guys. Actually, I'm fairy sure the reactors are pretty competitive price-wise, given the size of the things. The reason I have to charge what I do is because I use really high quality materials, which unfortunately are expensive. I just bought a sheet of Spartech polycast 3/8, and it cost about $300. But, given the work that goes into making these things, and especially the fact that any failure on an aquarium product can mean serious problems, I think it's worth it. For anyone that's interested, I would highly recommend taking the MACO acrylic fabrication courses with Brian Ferguson. He designed the stuff that I make, and probably anyone with a knack for these sorts of things could make their own just as well once they've taken these classes.