The thread title says it. Why are hang on overflows so expensive? Someone there is making some huge profit. Looking at them there is nothing there and then to top it all off they require you to purchase a bulkhead fitting besides. That fitting can be molded right into the overflow housing. OK can anyone give me an guess at how many I could sell if I designed my own , molded the bulkhead fitting into the the overflow box, made one size fits all. Say if I sold them over the internet offered delivery anywhere in North America for 30.00 Canadian a piece. How many do you think I could sell? I know 30 dollars would give me more profit than I need. Expensive things seem to be for a few other aquarium items I see also.