Actually, we learned that even in the Two Rivers Tinker-made or Tinker-mended work is highly prized. Even the blacksmith's wife considered her Tinker-made pot her best one...

They probably sell most of their work to peddlers, who would prize them since it's quality work that would sell well.

The Tinkers lead a very frugal life, with no luxury. They don't need tons of money, just enough for their clothes and a part of their food, the occasional tool etc. For the rest, they are pretty self-sufficient.