This. We're relatively wealthy (typical middle management salaries) and it took a string of doctor appointments over many months to get a diagnosis for our son. Several of these were multi-hour sessions. In addition to the time off work to attend appointments, there was time on the phone, time on the internet, time talking to school counselors/teachers, scheduling IEP meetings at school, and probably other stuff I've long since forgotten. There wasn't a lot of out-of-pocket cash cost (because decent insurance, not guaranteed in the US), but the time and mental energy expended was significant on its own.
And, 100% anecdotal, but my wife's brothers both have similar personality traits as our son. Neither was diagnosed (and as far as I know, neither tested - this would have been in the 70s and 80s). Both ended up as typical middle-class, working-class Americans (own modest homes, but no appreciable wealth beyond that).