I just emailed Gene Davis concerning them for a Weaver T36 I have coming and he said they are $100. Here is what Benchrest.com in the scope classifieds has listed for them.
"Now available for LCS, Weaver T, Sightron BR, Nightforce BR and soon March. 3 years of engineering resulted in our Re-engineered base curve, Precision ground, dual poly carbonate hybrid Carl Zeiss lens with anti-scratch coatings, coupled with a #3 optical magnification. Precise placement to sight picture optimizes your scopes ability to reduce parallax and mirage. The booster presents a sight picture that is boosted in clarity to a much higher level compared to optics without this booster... The housing is CNC machined from 60-61 aluminum that has been custom designed for each individual model of scope. When it comes to competitive shooting, and you are competing against these boosters without one, then you are handicapped beyond comparison."