So let me get this straight.
So you have two severely autistic kids, with all the financial and emotional burden that entails.
And you want to pay a clinic a large sum of money to add to your brood?
Why would you do that? You don't have enough expenses and work in your life?
As the mother of three (probably four) daughters on the autistic spectrum, I think the notion of eliminating boy embryos to reduce the risk of autism is dumb.
If you have autism in your family, it can affect girls too. Duh.
The thing about autism is that it's such a range. Autism, even moderate autism, is tough. Mild autism accompanied by high intelligence is actually quite the blessing. If I could wave a eugenic wand, it might even be to cause my future children to have Asperger's (but of course I wouldn't because notwithstanding its wonderful qualities, it does come with built-in disabilities, and who would deliberately give their kid a disability?)