I built a True Temper S3 frame that came in at 1406 grams, about 3.1 lbs. Stuck SRAM Red and some 1200 gram clincher wheels on it. 14.8 lbs total. Not sure of the cost, probably around $2500 total. If the OP really wants to use Reynolds tubes, getting under the UCI limit will be close to impossible. If a steel frame is the goal, yes, it's very possible.