128GB SSD models sell for, on average, $225. Prices are dropping, however. So give it a little time.
So did the 64GB SSDs back in 2009 when the 64GB iTouch was released.
The iPod Touch uses 2x 32GB, not a 64gb stick.
For the 128gb iPod Touch to be sold, it'd be 2x 64gb. And that would be either late this year or next year.
When a lot of people need it.
I don't think there are a lot of people that need 128 gb.