No best price. I get mine at the Scottish Tartans Museum with my Lewis kilt hose. Same folks make them. Should be a link to the STM on this page.

Some folks buy some yarn and a funky plastic knitting guide and knit their own. Suppose that would be the cheapest.

Easy way to wear them is just wrap them around and make a single knot like when tying your shoe, then push the ends under the other part of the garter. Holds well all day.

Ron