Well, I thought I was the only one with this problem...

I think it is doable, but you have to be very clear on your expectations and Honest about the invoice, etc.

Let's say you came to me and said:

Hello, superflit there is this project it is $xx xxx,00 Euros we split. I do zzz, and you do the web or backend.

Once we agreed we have to set the scope, tech, and deliverables. Because we are looking for the long-term partnership, I had to trust you, and you have to trust me. So we have to be clear what we are charging getting for every project and expectations.

My email is on my profile enter in touch if you want to.