Stinger

These come off hornets and spiked slimes, which means you collect them while you are in the Underground Jungle for other reasons rather than farming them deliberately. The list of things that want them is long but mostly one-time: an early jungle shirt, the Snapthorn, the Amazon. Clear those recipes first and then decide what the leftovers are for, because it is easy to burn a stack on consumables and come up short on a weapon you actually wanted.

The obvious sink is the Abeemination. Being able to summon the Queen on demand is worth far more than the raw material, and she funds the entire bee gear tree including the armor set that carries a summoner into Hardmode. Do that until you have what you want from her.

After that, Flasks of Poison sell for a healthy margin over the raw drop, though every one costs you a bottled water as well, so it is only worth setting up if you have a well and a spare afternoon. Poison Darts are the other outlet if you are still carrying a blowpipe and nothing better.