3d scanners are either extremely poor or exremely expensive at this point in time £5000 would get you a result worth machining £500 will get you something with very poor resolution not worth 3d printing let alone machining. A few cheap self builds around that can give results with a webcam and line lasers and get close to the sub £500 scanners, I have an £300 iSense sitting here that was a freebie thats good for displaying on screen with photo mapping but the resolution is so poor that its useless to produce a solid of any sort.