Is there any use for Hydra Claws, besides merchant?

And alongside the topic question, is there a market for this?

Collectors (I assume you mean the dessert hydra claws).

And if there is a market for it, it's in Augury or Amnoon.

there is a collector, near the teleporter, straight (just about) east of augury. go out of the north entrance (where all the hydras are) and turn right/east. keep giong east and you come to a small cleft between two rocks/mountains and the teleporter/collector is a little further and a small right turn.
gl
bilbo

Well, its a given that every NPC's specific drop is a collector's item, but who needs 20 Perfect Water Staves? :/

So I take that this is the only use.

The collector has one of the best healing ankhs in the game, (+12 energy 20/20 healing prayers)

Use to sell for 3-5k at one time.

Hydra claws will salvage into scales also. So if you need scales for armor crafting you get (if I remember correctly) 5 scales for one hydra when salvaged.