One aspect to the question of a break-even point on a bought pass is a different question then evaluating a pass to buy in the Future. This is because the ownership of the Pass itself changes your behavior, which makes breaking even somewhat self-fulfilling.
If you don't have a pass, when the conditions are not great you end up not skiing because you aren't going to stomach a $100 day pass.
Then you end up not going and you smartly say in April that you came out ahead, and enjoyed spending your weekends watching Football at home. When the days are good enough to consider paying the day rate, then you complain that the place is too crowded, wait in lines, and then things are skied out in an hour.
On the other hand, if you have a pass, then you end up going more often when the conditions are not quite as "perfect" and you get more days, and in April you say it was worth it.
The only way you lose is if you bought a pass, and yet you still went fewer days then rack rate.
So I will say you have to evaluate it just on Rackrate. If you went even more than 1 day then rackrate, then you also have to consider that having the pass also encouraged you to go out and use it, and you came out ahead not just in money, but in living life too.