We have opted out of well-child visits since our 4th child was a baby. For us, they were really a waste of time, as they were geared towards vaccinations and insurance requirements/collecting co-pays. We do not utilize insurance, but rather utilize a health care sharing ministry for needs. These visits would be out of pocket.
We have the children established with a provider at birth, and then never go back. Should we ever need specialized care, we have a pediatrician set up. The one time my child needed care for severe strep throat, I was able to identify the need, and we utilized an urgent care locally-staffed by family physicians. When asked at check-in about vax's, I said, "We don't vaccinate" and not another word was said. It was affordable, care was great, they called to check in on him the next day, and we didn't have to argue, or set up return visits, etc.
I understand why people would want the well-baby checks, but for us, they never did anything to justify the cost, that I am unable to do at home. I weigh and measure my children their first few years, and we've had enough children now to realize what is normal variations on individual growth, and when we would be concerned about anything. We did use well-baby visits when our first were young, mostly because we were still selectively vaccinating, and it goes hand in hand.
Best wishes with whatever you choose to do!