I am definitely not the foremost authority on the subject, but I'll say my recent experiences:

Coming back from COVID, I sold at MCFC 2021, which has never been a big selling con for me. I ended up selling the MOST I've ever sold at a convention, and I started in 2011. Just conbadges, an illustration or two, and a few buttons, all take home, no at con work!

A month and a half later I went to MFF 2021, still riding the high. Surely I couldn't do better than that, right? WRONG! I sold even better at MFF than I did at MCFC, same deal; all conbadges/some illustrations and buttons. But something felt weird. I never sell well, so WHY am I selling so well? Sunday I trawled through Artists Alley before it opened and I was shocked to see I was one of the cheapest artists in the place! By a lot.

Overwhelmed with the amount of work I had post MFF 2021, I made the decision to raise my prices. Not by that much I thought, because I'm still cheaper than a lot of my peers.

MCFC 2022 rolls around four months later (the dates were weird because of pandemic delays), I sell there again, and it's one of the worst sales cons I've ever had in my 11 year career. The next con I sell at is MFF 2022 and it ended up being the worst MFF I've ever sold at; I didn't crest $500, making it so I didn't break even for the trip.

This year I'm trying to get merch made, stickers, etc, but it's hard because it all costs MONEY which I don't have because I haven't been selling well and am paying for both me and my partner's bills.

As for price points, I charge 50-70 for badges depending on size, and 100+ for illustrations. Buttons are 3 bucks a pop or 2 for 5.

For me, I'm trying to avoid take-home stuff, because we're going on a big trip a month later, and I don't want to be stressed out about trying to get stuff done O.o So, I'll be limiting my slots...if I can't get it done during Artist Alley, I'll see if I can set up in the Zoo for pick-ups of the finished items. Or, at least, that's the plan >.>

When I gave up on selling at cons, I threw away a lot of my signs that had my prices, and since it's been forever since I've done this, I wanted to see what the going rates to other artists are, so I can get a good idea of it. So far, I'm making a list of types of badges that I'd like to offer and I'd like to see if I can make samples to show at my table. Once I get some samples done, I can get a better idea of how much work goes into making them and stuff, as well as how big (or small) they'll be, etc. and hopefully determine the price of them.

....of course, this is assuming I can actually get a table in Artist Alley at FtM >.> Here's hoping!

Most artists I know of do all the usual fare. Badges, various art pieces, sketches and the like. Some will have a custom piece specific to the Con, too. As for prices, those are pretty varied. I've seen prices (CAD) from $5 and up. The most expensive price I can recall was about $1500.