Yeh they are expensive, but you can't be a full time detailer without one. It Is as important as your polisher! Lol
I wouldn't recomend anyone other than a detailer to buy one, purely for the cost of it. But if you are charging people for work, you need to know it's right. With halogens you can't always make sure it's right. That's also why I've got huge metal halide floodlights in the unit, that show up EVERYTHING! Haha. You just have to work to that benchmark