Perfect Disc for Panel Beatings

I had a recent slight accident and i dented the door on the driver side. Since i don't have enough budget to hire a panel beater then I'm planning to do the panel beating on my own. Would just like to ask ya'll if Smith & Arrow is a good buy. I have this link (http://stores.shop.ebay.com/smith-and-arrow__W0QQ_armrsZ1) which states is the cheapest on the market and is actually very good to use based on the all the positive feedback. I don't really have any experience with these tools so i hope anyone can help me with this.