$185 is a lot of money to pay for something that you can build out of cardboard or plastic "for sale" signs. You can make a triangle with zip-tie and duct tapes to hold the bottom and top. I have made many of them and carried my PBJs, orange juice, long pants, rubber boots, sweatshirt, and mittens for cold century tour rides.
My plastic storage triangle was taped and zip-tied to a bike rack I found in a dumpster. I got the plastic "for sale" signs for my recumbent storage triangle in the neighborhood recycle bins on trash pick up day.