We seriously lost count we did that many. It's all there in my history although I aint counting them. It was too much and we got to really disliking them in the end. I suppose the fact is that it's a numbers game and theoretically the more you do the better your chances but the fact is it's pure RNG and you could buy the game today, do your first Heroic strike and get a catalyst. All I would say is don't go out of your way to get them. Just wait for them to drop because it isn't worth the grind.