AITA for snapping at my teammate in a group discussion over enamel pins?

I'm part of an 8-person indie game studio with friends from uni. I'm one of two main artists. One teammate, I'll call him Mark, does programming/marketing. He's likeable overall, but chronically late, interrupts people, and fixates on details that don't matter while brushing off ones that do. We got along fine before working together ,this only started once we became teammates.

Our game got invited to a convention, and we decided to sell character pins there. Mark and our team lead proposed 500 units at $10 each. I pushed back, my sister sells art at conventions and I've helped her enough to know that price wouldn't cover production costs for a broke indie studio. Steven insisted it'd be fine, citing cheap prices from manufacturer websites (which are teaser rates, not real quotes) and a developer friend who supposedly sold well last year. I asked for that to be verified.

30 minutes later, our team lead pulled up the actual chat with that developer, they'd only sold a small portion of their pins and gave some away. The opposite of Mark's claim. The meeting ended unresolved.

Later that day I raised it again in chat, suggesting we lower the quantity and raise the price to $15. Mark repeated the same disproven claim anyway, which made me think he didn't pay attendtion when the team lead pull up the chat, and kept refusing $15. I snapped, asked why he was comparing a handmade pin to a video game, and basically called him naive for basing pricing on an unverified rumor instead of the numbers we'd just confirmed. I also said the fact that he kept quoting the same thing over and over again pissed me off. After that I left the chat and went to bed.

The rest of the team stayed silent through all of it, even after the numbers were confirmed. Now I feel like I'm being seen as the problem.

AITA for snapping like that?