DH had some undies where the fabric had frayed over the elastic. Recently I got in on a deal for proper waistband elastic. So, I took the idea from some of his other pairs to replace the whole waistband part with this other stuff.
Okay, it wasn't as easy as I thought it would be. The 'good stuff' is very firm. I struggled to stretch and overlock at the same time. For the second pair, I stretched and sewed on the sewing machine first, then did the stretch and overlock part.
Confession: I have decided it is easier to buy new. Sorry.
I did learn how to do this though! and I will make sure to buy the undies with that sort of elastic so they don't wear out so quickly. So, still a bit of saving.
Oh, and I kept the buttons from the pairs that I tossed.