However the truth does have a habit of getting out....
Interesting thought, however, I'd prefer it not be at the expense of my child. The one and only time his MS school did not have the appropriate 1:1 available, he disappeared. He ran out of the classroom during a busy morning when there was a school programme (a situation that was guaranteed to create huge anxiety in him) and that meant the school gates were open and people were everywhere. He was a runner, and they knew it. It took ages to find him. That was 3 years ago, and I still remember how panicked I was (and the school staff was as well).
They made sure it never happened again, but it could have had a very different ending. He has no sense of danger and would walk off with anyone or walk out in front of a moving car. I personally would not want my DS to pay the price for them cutting corners and not having the appropriate support in place.
I think those that think that sharing the TA is "better than nothing" are being rather flippant. If instead of teachers, your school brought in unqualified people off the street that just sat in the classrooms and monitored the children, would you think "well, it's better than nothing?" After all, if it's all the school can afford and they don't have the funding, right? 