I guess I will chime in on topic. When I first got in hobby back in early 90's, I started building for a friend who would rather pilot. That worked to my advantage, I liked to build. great partnership. I then met a owner of a small local hobby shop. We became good friends and started the barter system. That then grew into referrals from the LHS owner.
I was particular on what I would build. I had to appreciate/like the subject aircraft in question.
Long story short, I was younger then, had limited funds for the hobby. So building for others allowed me to finance my needs in the hobby. With that said, I probably averaged $5/hr. I built off and on for about 6-8 years. Only reason I stopped building was a leave of absence from the hobby I took due to family and kid priorities. Not building for others these days. Just trying to sneak in enough time to build my own projects.
IMO, you need to find those with disposable income and appreciation for the amount of time and craftsmanship it takes to create a quality aircraft from a kit. If not, trying to make minimum wage will always be a struggle. definitely always had all materials covered in advance.