I'd like to bring this topic up again, because its nowhere near resolved.
I am not sure how contribution value relates to price (vault credits), but for the rights of crafters I must speak up to this; personally i don't even craft, so this is not for me, its for the family.
Using vendor value is not the proper way to set vault credit prices, in fact, market place items does not reflect vendor prices, example: A glob of ecto vendors for about 2.5s , my lv80 exotic coat vendors for 2.4s, but guess what? My other lv78 exotic coat vendors for 3.8s, do you see what I am trying point out here? The vendor prices aren't reliable for comparison.
Back to market place, ecto is 14 vault credits and 2.5s vendor in game, but an exotic lv80 armor is over 1000 vault credits and 2.5-3.4s vendor in game, just this case alone shows how things can easily go out of hand when you try to price things on vendor value. I am assuming its over 1000 vault credits just because it was calculated from the entire material cost, while the actual vendor cost of the product is ignored <- and it has to be doesn't it? it doesn't make sense for an ecto to cost the same as a piece of armor, but that's what can happen when you base pricing off of vendor prices.
Then there are the lodestones, these things are probably the most ridiculously priced objects on the marketplace , 14 vault credits for a lodestone while its at most 1g 50s per piece in game's Trading Post. There are reason why these things are priced so high, its hard to get, really hard to get. I see people ordering 10 corrupted lodestone or 10 destroyer lodestone on the site, this is abusive and exploiting the marketplace, because room was provided for such exploitation. If I see someone order 1 it makes more sense, because if you want to make runes, some times you need 6 of these, and you have no idea of capability to farm it, but other than runes, lodestones are required at large amounts to make special exotics and lengendaries, required at 100-250. These are superficial items, if anything they should be priced even higher. People that do know how to obtain lodestones will not want to fill these orders, sure its for the family, but why not just help craft an armor that gives more contribution?
I am suggesting the price to at least somewhat follow the trading post, although dictated by demand, its also a good indication of how "difficult" it is to obtain the said items, vendor price does not reflect this one bit; it just doesn't. I don't see why the crafters' reward is not based on their efforts but arbitrary vendor values Anet declared.
With all said, I am not making this post to blame anyone, I am saying the marketplace price reflects poorly on areas on the efforts crafters needs to make, and now I have raised such concerns and provided the information I know of, its up to the elders and the leader to investigate more into this for the sake of our crafters; but since I am not a crafter, if my concerns are not the slightest similar to any of their concerns, then treat this as void.