Leaving aside the challenge of getting money to pay for the help families with autism need, there's also a challenge in finding that help.
On average, it takes me 2-3 months to train someone to the point of being able to leave them alone with the boys. So all the offers of "just call me to babysit" are nice (and appreciated as support) but aren't actually useful. Often I'll ask those folk for help watching the boys while I'm busy doing something else (such as working or writing or dealing with a major home project). I've discovered this doesn't sit well with a lot of people, so I've had to learn to be careful who I ask.
Then there's the challenge of predictability. The boys don't do well with last minute changes, especially if excited. So anyone I ask to work with them needs to be reliable.
I've found there are a number of places I can find help: local high schools (I contact the principal to ask them to refer reliable, grounded teens who are looking for part time work), local colleges/universities (two of three higher education organizations offer programs for training workers to work with special needs children, they often want the resume addition), and local boys and girls clubs (such as Scouts), where again, I ask the leaders for suggestions.
I have to train these people to work with my boys and the turnover rate can be high. (I'll be lucky if I get a year or more.) But they're more plentiful (and often cheaper) than professional respite programs and workers.