I think the simple answer is that, like in all walks of life, some people will earn more than others. You set your own pricing structure and work accordingly. If that means charging £50.00, £150.00 or £250.00 for a sofa then fine. If you get the jobs at your prices and you and your customers are happy then I can't see a problem.
When I used to visit my Brothers family in Herford Germany , he paid 40 euros for a window cleaner ,and double that to have his small lawn cut , the costs of doing business were so much higher there , in turn he got a higher than British salary , the market is different .