Well if you have a lot of money available, maybe it's a money issue in that you aren't paying enough. As a thought experiment, what would happen if the TAs were paid $100,000 each? Would you attract more qualified candidates?
Good plumbers make a lot of money because it's a dirty and disgusting job that nobody wants to do.
It turns out that the university has a lot of rules about how TAs (and how much) TAs are paid, and further TAs are unionized (they are members of the United Auto Workers -- believe it or not!) and that we are bound by contract restrictions.
Sounds like you are in a jam. As far as I understand it, given the current syllabus, either you have to lower your hiring standards or do the work yourself. I've done both of those things in the past, and it was always a pain. Ultimately I settled for reducing the amount of TA work that had to be done. A lot of grading is probably optional, you might not be required to have a midterm and final, stuff like that. Rather than let yourself be victimized here, try to be creative with the resources that you do have, you'll figure something out.
Foobar -- that's a great plan, and let me assure you there is a lot of activity going on in the background.
If you want to talk about this, and you're on the Berkeley campus, I sit in Soda Hall 739. Alternatively, I hike most evenings in Tilden Park for exercise -- if you'd like to join me sometime and talk about your ideas, I'd certainly welcome hearing them.
Oh, I'm not in your class or even at Berkeley. I'm just discussing things on an internet forum. Good luck though, because from the comments here it sounds like your students are pretty angry, and admin is being unhelpful.
Good plumbers make a lot of money because it's a dirty and disgusting job that nobody wants to do.