I personally would buy hats (baseball caps), shirts (long and short sleeve), and jackets/hoodies. I think those are the three main things most people want as well.

As for price, you should make it premium (like, not just a screen printed T-shirt) and charge what it’s worth. Don’t just search for “best merch stores 2023” and choose the top result. Find a place that makes high-quality stuff. The best would be a local store (in your location) that makes it themselves, and then ship it to us. And make the clothes something that people want to wear every day (not too flashy, not crazy colors, etc). If you do that you can charge pretty much anything and it’ll work. TLDR: prioritize quality over price.

For country, you have the analytics so you probably know best, but the USA, UK, and Australia are musts. I would say to ship it anywhere but charge for however much shipping costs.

Setting up your own shop is more expensive than just paying Teespring, Redbubble, Printify, etc to do it, but it would come out better in the end.