Lew,
As a place to just hang flies while the heads dry, it's certainly functional and nice looking. Reminds me of a paper towel roll holder. I'm not sure how the foam would hold up over time. It would also take up space on the table.
I wouldn't buy one. I ran a stretched out spring over my table to hang flies from. Holds hundreds and it's not on the bench and in the way.
The other guys are correct if you are trying to make one for drying epoxy (when folks say 'fly dryer' this is usually what they are referring to), then it's needs to be motorized and move on a horizontal rather than a vertical axis.
The only way to know if it will sell is to test market it.
Buddy
It Just Doesn't Matter....