I agree with you that I probably wouldn't want to pay to repair an inexpensive item of clothing, but I can't articulate why. If an item is poorly made, it may not be worth repairing, but price doesn't always correlate to quality.

I've been thinking about this lately with a wristwatch. I have a 10 year old Seiko mechanical watch that cost me $50. To get it serviced will cost more than I paid for the watch, however there's nothing about the watch that makes it less worthy of servicing than a watch that would have cost 10 or 100x more.

It's sentimental attachment for some objects - the daughter figured out how to repair T-shirts and sweatshirts (she learned the trade from her self taught father but he could not do these repairs prior to her breakthrough).

Why not? If you worn it until it needs repair you’re probably fond of it.