Thanks for this tip. I had purchased a pair of these at Costco a couple years ago but got the wrong size (L instead of M). My wife managed to take in an inch off each side with her sewing machine (I had tried to return them for the smaller size but they were no longer carrying them). I just picked up two more pairs. They've changed a bit since I got the earlier pair, adding in two zippered pockets. In my opinion, these are a great deal for $20. I paired them up with this belt, which was on sale at Amazon for a Lighting Deal last week for $8 each. Even at $12-$13 they're a good deal.
https://amazon.com/gp/product/B0183A548Q/