Search the Internet for psychologists and psychiatrists in your community who admit to assessing and diagnosing autism. Then, prioritize your list based on location. After that, start calling your list and flat-out ask: 1) if the professional has experience with autistic adult diagnoses; 2) what the price of an autism assessment would be for you; 3) if there is a cash-payment discount (almost all professionals have cash discounts); and 4) what diagnostic tests they use to autistic assessments (ask specifically if each professional uses the ADOS-2 tests; they are among the best). After all that work, you should have a short list to consider. This makes it all much more manageable.
In my search last year, I chose to attend my university's ASD clinic despite the $1,000 price, but I also considered private-practice psychologists and psychiatrists because a few of them had prices around $250-350. Having lived in San Jose, Calif., in the 1980s, I know how prices differ. But, if a Salt Lake area professional bills $250-350, a Bay Area professional is probably about double the price. You can always schedule an assessment as far in advance as you believe you need to save the fee money, I did this with my own fee money.
In any case, good luck and stay in touch with us if you have questions.