How about the Trekmates Grasmere ankle gaiters, widely available at about £10 and weighing less than 100g? They have front velcro openings, so are easy to put on. The fabric is not as breathable as some, but I've never found this matters much on your ankles. Durability seems fine to me, having dragged them through heather quite a few times, but they're so cheap it hardly seems to matter that much if they do rip.
Or, if breathability is the holy grail, the very similar Windermere ankle gaiters made from Gore-Tex.
I like the Integral Designs eVent short gaiters myself, cos they work well with shoes, but you have to put them on before you don your footwear.