I have sold at Gem and mineral shows, I have found that the quantity of items in not as relevant as Quality and type. My stand was 3 tables, and I had 22,000+ cts of gems, and over 130 Lbs or minerals. The vendor beside me had 1 table with 2 trays of gems and a few boxes of minerals, and we both made very close to the same profit. I always feel that the more you have the better your day will be. Not sure if that helped with your question, but that has been my experience.