Selling Used Finis Kid's Monofins

[AniaR]

I am looking to sell a lot of 9 finis mermaid monofins. The blue ones are brand new never been used, the others were used in my swim school. They all have varying degrees of wear and tear. They sell new for 31.99$ USD. I would like to sell the whole lot for 200$usd plus shipping. It is easier to ship them all in a large box together due to their awkward size. Shipping cost will depend on where they're going to, we can get an estimate. Great if you want to try giving mermaid lessons with your company.

[Mermaid Riia]

I tried to find blade measurements online for these, but for some reason couldn't find any. Do you have any data about the width etc?
I'm having some trouble with magictail monofins staying on (some customers seem to wiggle their way out of even the smallest sizes) and was thinking maybe these could do the trick.