maybe try your local 'sheet metal' workers?
I wanted two of these. As has been said, web prices are high. Local marina wanted about £140 ea. to make these up. Sheet metal place said £35 each based on a (very rough - I'm no techy) drawing I'd made and my leaving an empty container with them for a couple of weeks.
It's not 'mirror finish' stainless, but after 4/5 months it still looks good enough to me, holds the boxes very well, and at £70 pair I'm not complaining. Maybe the same approach where you are will work ??