The fangs are the reason to go. What they build covers the whole minion setup for that point in a run, so one thorough clear of a nest usually leaves you with the full kit instead of half of it.

surviving the nest

Black Recluses are the problem. They hit hard for that stage, they poison, and they cling to the walls of tight tunnels and drop on you where there is no room to back off. Widen the passages before you commit to a fight in them, and bring something with reach instead of trading melee swings in a corridor.

leftovers

If you finish with far more fangs than the recipes need, the better return is turning the extras into Queen Spider Staffs and selling those rather than dumping raw fangs on a merchant.