You can get 100 scales, 3 pliers, and some rings for more or less $30 to start you off, and I'm talking about the cheap stuff. Bare in mind the materials I have were given to me as part of the class payment, so it was at the instructor's discretion to what he chose from this website:
http://theringlord.com/Dimensions and how heavy? I'm guessing 2''x3''
Rough measurement of 3"x3".
Heavy? They're aluminum scales, so not heavy at all. It's less than 100 grams now I think, but I would have to weight it properly on a scale that is a lot more sensitive.