I didn't think to look at the OP's (sold) listings. You're right, I think the coins and bank notes would definitely be a good place to start, especially the pre decimal stuff. There's very few sellers that can get those kinds of prices so would certainly get him noticed. I've picked up quite a few bargain coins and notes over the years, which I could easily have resold for 4 or 5 times what I paid for them. I didn't buy them to resell though......not yet anyway! If the OP is in the right place at the right time, he could get some great bargains to resell too.

I didn't know what to sell when I started selling. Initially, like a lot of people, I was just selling stuff around the house. I decided selling was fun, so started buying to resell. I didn't know what to sell, so picked several things, listed them and watched what happened. Some of the things are still relisting now, others turned out to be hot items. So, of course I mostly concentrate on the hot items now. I probably went through 6 or 7 things before I found my niche.