Yep, if you and the bowyer are measuring draw length from the AMO location this would be light-years from what I'd expect. I've very carefully done these kinds of measurements using digital scales on all my bows. I typically check them at 28" (AMO spec), 25.5" -- my draw length, and 29" to see what kind of stacking is taking place. I've found 2.5-3 pounds of difference per inch of draw within these measurements.
I've noticed 1-2 pounds difference (usually lighter) from how the bow is marked. The most accurate measurement vs. speced by the bowyer (my sample size is only 9) was a recent Schafer Silvertip I was trying out.