So at the most recent Pax I had used a cumberbun and it somewhat worked. It was really thick and I unfortunately lost one of my pins over the course of the 4 days. Is there a Belt, Sash, or Cumberbun that I would be able to use to be able to display and easily trade from at the next pax I attend?
I've seen a number of people use the PAX scarves as a place to hold their pins while trading around the convention. Depending on how many are on there it can become rather weighty though, but so can the lanyards it you choose to put many pins, or many large pins like Bowser on them.
If you are concerned about losing any more, I would recommend using locking backs rather than the standard backs - yes this means a little extra time getting them on and off while trading, but I have found that mine have stayed in place quite firmly.
Penny Arcade do sell locking backs, or you can try several online sites if you Google the term 'pin locking backs'
Laughter and Sunshine!