I would not trust any hard figure for achieving PPL-H, either basic or add-on. This is similar to PPL rating where virtually all flight schools quote a hypothetical figure based on minimums that nobody achieves. If you do want real numbers, ask them for contact info for recent grads, and ask those contacts about their actual hours, etc.
Let me add another point re expensive "further education". I have added both Heli and Glider ratings add-on's to my power rating. Flying helicopters is a blast - unequaled sensation of being able to hover, go straight up or down, sideways, backwards etc. Nothing can beat that, and the satisfaction of mastering those skills and doing those maneuvers proficiently (along with many others, like autorotations) is immense too. However, from the perspective of bang for the buck of the greatest return in both usable skill (in your fixed-wing power flying) as well as raw fun (assuming you have aviation in your blood), I believe gliding/soaring is by far the better deal. Sure, ideally, if time/money is available, you'd want both, but under fiscal constraints, I think gliding/soaring is the best choice.
And BTW, even gliding/soaring is not a single pursuit. It can be divided into several levels, each of which is vastly more fun than the previous, once mastered. Getting PPL-G is just the lowest level, which is awesome, but still nothing compared to the higher levels.