Unfortunately, so many people have NO idea of the costs and time involved with hand-crafts. They're so used to quick satisfaction, shoddy industrial craftsmanship and warehouse pricing many can't grasp the concept of what true quality and good, fair value is. Add to that some people seems to have a bizarre sense of entitlement.
I do embroidery, cross-stitch and needle felting. I'm an amateur still, but I've received multiple requests for custom items from friends, family and acquaintances. Other than gifts, I've yet to accept such requests. The reason is because they have NO consideration or appreciation for how much time and money goes into it. They want the best quality materials, extensive detail / expansive projects, don't want to pay for materials and would rather just pay a few dollars for the finished product citing "I could get X like it at target / random other store". One such example being a friend that wanted a detailed felted tree ornament, with felt core, multiple colors and lots of small detailing... And only wanted to pay $3 because thats what the shoddy, poorly made felt-over-foam ones cost at target. When the cost of materials alone is brought up, she assumed that since I had materials already, she shouldn't need to cover materials.
Your work is beautiful, and I think $90 for those pieces shown is a steal. If someone gripes about your prices, don't fret over it. Just pass them by. There are still people that appreciate such skills and work and will gladly pay for it.