Well the cost depends on the clinic you go to. You usually have to pay per treatment. If you want the hair permanently gone then you have to go regularly for treatments. If you can't afford to go regularly or just want the hair to start growing out better than you can just go in for occasional treatments. I go for treatments but my hair has not permanently disappeared. I go for my upper lip. When I get a treatment done my hair is usually gone for about 4 to 5 weeks then it grows back. But it grows back really fine instead of really thick and its not as dark. For me personally there is a bit of pain. It kinda feels like a hot zap. The longer you let it grow the more its gonna hurt so if you do go, you don't have to let it grow super long. If the pain was really bad I wouldn't continue to go but it doesn't bother me too much. The treatment goes really fast but that's cause its just my lip. For body hair the hair stays gone much longer than 4 to 5 weeks. It shouldn't take too long to get a treatment done. Probably around 20 minutes for your armpits.