And the Profilux are on sale right now! ;)

Here is a possible different solution that I have been researching to add to my system:

http://www.jlaquatics.com/product/tz...or+-+5074.html

From the research I have done, it is not great for larger higher demand systems, so it would depend on how big your demands are for dosing. If you already have the tunze top-off, it isn't that much more for the calcium dispenser.