So since a Wyvern is considered a dragon, and a dragon's hide can make 1 suit of armor 1 size category smaller than the dragon. And a Wyvern is typically Large, it can make 1 suit of hide armor. Hide is 15gp, and MW is 150 GP, so 165GP total, double that since it's "Dragonhide", half that as material, and less than that since it's a Wyvern and not a true dragon... So, roughly 150GP per wyvern hide.
Cost Dragonhide armor costs twice as much as masterwork armor of the same type,
One dragon produces enough hide for a single suit of masterwork hide armor for a creature one size category smaller than the dragon. By selecting only choice scales and bits of hide, an armorsmith can produce one suit of masterwork banded mail for a creature two sizes smaller, one suit of masterwork half-plate for a creature three sizes smaller, or one masterwork breastplate or suit of full plate for a creature four sizes smaller. In each case, enough hide is available to produce a light or heavy masterwork shield in addition to the armor, provided that the dragon is Large or larger. If the dragonhide comes from a dragon that had immunity to an energy type, the armor is also immune to that energy type, although this does not confer any protection to the wearer.
|Mark Hoover 330|
Obtaining a Trophy is different than just skinning the hide, but a CR6 monster generates a trophy potentially worth 400 GP. Trophies are usually something unique to the monster that they are known for, or something you could mount and display as an art object.
If PCs are REALLY interested in harvesting a wyvern and they've got some time...
The hide could be used for armor, as MS said above, 55 GP
A Trophy, made from the head or the stinger, properly harvested and preserved, could be worth 400 GP
The poison, if harvested, has a sell cost of 3000 GP per dose
I have MANY times encouraged my players to treat some monsters like moving treasure chests. There have been times when I have forgotten to increase a treasure hoard after several no-treasure encounters and my players have fallen behind WBL. To make up for that, I point my players to those trophy harvesting rules. While a single trophy doesn't usually catch them up, this mechanic gets them thinking about other things they can do with the monster's carcass such as food, bone items, interesting and lucrative uses for their blood or organs and such.
The trophy harvesting rules do give some "magical affinities" for some creatures' parts. For example, a troll's liver could be used to pay the crafting costs for 360 GP worth of magic items that revolve around healing subschool spells. If a wand of Cure Light Wounds costs 375 GP to craft, now it costs 15.
The magical affinity lists are not intended to be exhaustive so as a GM I make up uses now and then. Since Wyverns are associated with Poison, I'd have some gland that produces the toxin in the wyvern be worth 480 GP towards the crafting costs of items that revolve around Poison spells.