There's always time to add to what you get done later, so don't hella stress out about it like I did. There's always the internet and future conventions, no need to break your back and lose sleep. That's what Josh and I do with buttons, they're just going to accumulate over time until we have filled up our display. Then again, the new game is coming out somewhat soon here so I'm not sure how that will affect your project.
Have you selected the dimensions and prices for your magnets and stickers? How will you be making them? You can note me about all the technical stuff if you want to be more private about it, I'm just curious. C: