If all you want to see is the edge to check for chips and similar just about anything will do. If you want to see more detail then you need a better quality piece. With optics it's all about quality and resolution not magnification. Better optics mean better eye relief, clearer image, more detail, more light and easier to focus and if you wear glasses the eye relief is very important. I use a Zeiss, yes it's pricey but it's quality and at 10x shows me everything I need to see.