I've got to agree that it's not necessarily unreasonable to take pictures of Catherine out shopping. Unlike many royals, William and Catherine have the luxury of living undisturbed on a farmhouse in the middle of nowhere and aren't photographed there, or every time they go out. You can't have your cake and eat it. It's not as if she has to worry about how she looks in the pictures anyway.
As for the clothes...I find the pretence that she's feeling the pinch as well as us a bit irritating. She's a duchess: of course she could wear a dress a day if she wanted to, and it's not as if wearing a $300 sweater three times in public makes it look like you have to make sacrifices.
I also wish that she'd dress more ethically: her £195 Reiss Shola dress was made in a sweatshop for less than £15. I'd rather she wore good quality clothes that didn't scream high fashion. It's not as if Reiss deserves a royal warrant...
Do you have proof for that, a source?