My husband Wargames and he wanted a new case for his minis to travel to and from games with.  He showed me what be wanted.  My eyes nearly popped out of my head.  Just the small one tray case was $50.  So after taking some measurements, I decided that I could make one.  Famous last words.  We went and bought material, a zipper, bias tape and handle strapping on Friday and I started on it that night.  After a few hiccups along the way I had the top and sides just about finished and had the zipper on.  He was getting a little antsy and then confessed that he was hoping to have it to use today.  So instead of waiting to see if we could find some corrugated plastic to make the sides stiff, He cut up a rubbermaid bin.  I did indeed finish it this morning in the wee hours, but it certainly wasn’t all that pretty.  I learned a good deal about what to do in what order and there was a lot of trial and error.  It is functional and what’s what matters.  In materials it only cost about $15 to make.  In time, it took about 5 hours.  No picture yet, he ran off to play with it already.

edited to add pictures:

It was made to fit a 3 1/2 x 15 1/2 x 12 foam tray.  Stuart bought one today and it fits perfectly!