Well, the ones like that here, in Japan (imported from the USA, made in China ) are about $40 to $50 each, so I made one.
Sorry I do not have a pic of it, but it is just a simple thing like this....
I bought the roller for about $10, and made the stand up for about $5, well, that and a welder etc.
I think if they are $19, you would be ahead money and time wise to buy them.
The pessimist complains about the wind; the optimist expects it to change; the realist adjusts the sails.
William Arthur Ward