ClarkeB said:
There is really no mid-range iPod (you can get 512mb-1gb sans screen, then a jump to 4gb-6gb with a screen in different colours then it's a 14gb jump).
Certainly sounds like there's a mid-range to me. Current price points are: $100, $150, $200, $250, $300, $350, $450. There are feature breaks at intervals throughout, but basically Apple now has a full line of portables at any price between $100 and $500.
There isn't, nor will there be, a 10GB model until there's a mini-sized drive that holds 10GB, which will be a while. Logic? 10GB in the mini form-factor is currently not possible, and 10GB is too small for a full-sized iPod drive; if anybody is even making 1.8" 10GB drives any more, the price difference between 10GB and 20GB would be way too small to significantly change the price of the bottom-end full-sized iPod.
6GB to 20GB seems like a big jump, but it only reflects a $50 increase in price, and there's a physical reason for it--it just doesn't cost that much less to make a 10GB drive than a 20GB drive, so there's no market for an iPod that's twice as big as a mini and has 65% more capacity for $20 less than one that holds 20GB.
Try shopping for WD hard drives and you'll see the same principle at work: you'll pay $51 for a 20GB 3.5" HD, $48 for a 40GB one, $59 for an 80GB one, and $77 for 120GB.