When I was selling regularly I had a few bike parts that sold well and I had a lot of them. Not expensive, something like $15 plus $2 shipping. I've always done a set price in the US and international at cost.
That made it odd, because I was sending them to Canada and I think a couple other countries for less than $2.
When Ebay changed to pushing free shipping with DSRs, I did a small experiment. I listed some at $20 with free shipping anywhere. That Just barely covered a couple countries, but none I'd ever actually sold to. It also gave me a bit more profit. I figured sales would be less. Wrong
I sold about 3x as many, even with the old $15 listing still up.
So I switched everything to free shipping and added a little to the price.
That actually worked too.
Steve B