Work Clothes

It's been a busy week. Money has been fairly tight lately, and I find myself in a dilemma over where to spend money.
At work, I need something dressier than jeans, but not really a suit.
At home, I want jeans and comfort clothes. When I think of nice work clothes, I think of wool garbadine and cashmere sweaters, but this is really too dressy for my workplace (I teach middle school special ed). Well, maye not the sweaters.

A cashmere sweater can go anywhere.
I don't want to spend $100 dollars on a pair of trousers for my work, though. I want...designer jeans, which reminds me. Where do us larger people get good designer jeans? Recommendations?

Will I ever have enough money to just go shopping? Sigh.