Take my FIL as a case study
Was only diagnosed as Aspergers at the age of 58. In fact when he went for testing they said he was a very clear case and they didn't need to finish the test.
He did rubbish at school despite being quite intelligent.
Cost to government - loss in taxes for the well paid job he should have been able to get if he'd had the right support and not been labelled as naughty and cheeky
Unable to get along with bosses, lost a lot of jobs due to being 'difficult'
Cost to government - benefits when out of work, loss of tax revenue.
He got into lots of fights as a young person due to saying stuff that most of us would find rude.
Cost to government - various arrests, small stint in jail, and medical treatment
Became an alcoholic as he found social situations much easier when he was drunk, this then became all situations were easier when drunk (not say everyone with ASD will be alcoholics but just that if he had known he had ASD he would have understood himself better and not felt the need to fit in)
Cost to the government - several stints in rehab
Also because of his alcoholism he left MIL with 2 kids
Cost to the government - benefits of various amounts over the years. MIL always worked but still needed top ups as a single parent
He's also had counselling since his diagnosis to help him come to terms with it all.
Also BIL had a terrible relationship with FIL, he killed himself and I am sure part of the reason was that relationship. Unfortunately he killed himself before FIL was diagnosed and I always wonder had he known it would have helped put that into perspective and may have helped his mental health.
Now compare that to DS1 who has had a lot of help at school plus he will be going into a world which hopefully is more understanding and also protects those with additional needs. He will hopefully become a productive member of society giving back probably more than he has received.