I've outlined every detail of this aircraft as far as cost and weight. I find this method helpful if you ever need to determine why your plane is heaver than you think it should be. Now with that said low weight is not the smoking gun in getting a great 3D aircraft. I personally feel like in the end wing loading and the over all design of the aircraft really count for allot. This combined with the right size prop and power system will get you something that you will really enjoy. Hope these notes help.