I'm gonna get hosed for this, but I live in Marblehead and there are houses here that fit your needs. Marblehead is by no means affordable. I think you're being kind of dramatic. Especially about the post 1978 thing. Do lead tests, or scrape and repaint. Also, unless your kid is totally unsupervised, like don't let them eat paint chips? It's probably good advice whether you have lead paint or not. TBH they're more likely to have contact with lead from the dirt in your yard than the paint in your house if your house is anywhere near a road.