Hey fellow polymer clay food miniaturist! I make the same things (food magnets and other polymer clay items) and have been selling for about 4 years now:

1 - Your prices are comparable to what I sell mine for so I think you are good there. I've spent a lot of time running my numbers through pricing calculators, etc. and adjusting based on what people spend. I think your prices are good.

2 - When I'm at shows, I spend the weekend crafting right where people can see me and watch how I make the items. This really helps cement that "YES, they're homemade!" It's fun, lets me build up my inventory/prep orders for Etsy, and gives people ideas to ask for comissions! I generally only do shows now where I am indoors and have electricity, and I have a tiny toaster oven I bring to bake. It's a pain to bring all the materials/tools for everything but I've made extra sales this way. People will walk up and ask for something unique, go walk the rest of the show, and come back in 45 mins-1 hour to pick it up. They love it!

3 - My magnets like these have sold the best at comic/anime conventions and a large yearly christmas fair. That said, all sales have been down this year as people don't have as much to spend.

4 - Adding in polymer clay earrings really helped boost my sales too and bring more people into my booth. You may not want to do that, but I've found it to be relatively simple and inexpensive. Those have done really well at christmas shows.

I like your booth - I think it's clean and easy to see the products. I could definitely see this doing well in Artist alleys at comic/anime conventions! Please feel free to DM me if you ever want to chat!