Anna, just thought I would let you know that I totally get what you mean with the salesperson plus not the best day. The other day, I was wearing a pair of trousers that I'd grown to hate. (They weren't the best fit to begin with, but they were a placeholder, so I bought them. I finally hit the wall with them and they needed to go.) I was looking at new trousers and one of the salespeople insisted that I had to size down because mine were too loose on the hips. But they just barely fit on the waist. I should have insisted, but no. So I ordered the smaller size. It arrived. It was a disaster. Loose, squishy muffin top hanging out all over the place. Too tight on the hips. Totally demoralizing. They went back. So you aren't the only one this week to take home a less-than-perfect pair of bottoms on a less-than-stellar day. I've decided we all need a Rae clone to shop with us.
Have you tried the Vince moto jeans that look like those? I got a pair on NAS and absolutely love them. (They were a fashion stretch for me--not a core item like they would be for super-stylish you!) They are great for not pinching the waist and have a great balance between stretchy enough to be comfy, but not losing their shape.