The product descriptions both at here and DAZ are pretty good at listing exactly what comes in a particular package. I think it's reasonable to expect that a consumer would read the package description and be responsible for knowing what he or she has already bought. And, in any doubt, write the merchant to ask whether it's the same product that was sold elsewhere. Further, there is no other line of commerce in which the merchant has an implied expectation of guaranteeing the price of an item. There are stores that do guarantee prices ("If you find this product for a lower price anywhere within thirty days after purchase, we will refund the difference"), but these are special, clearly stated exceptions. However, merchants do have a responsibility to guard against false or misleading statements, and if the item was simultaneously being sold at DAZ while also sold here as an exclusive item, that's a problem. The original artist has the responsibility of letting DAZ know of the prior exclusivity deal with Renderosity, DAZ has the responsibility of informing Renderosity that it has purchased the item with enough advance notice that Renderosity can remove the exclusivity claim, and then Renderosity has to prompty remove the exclusivity claim. If anyone bought the item from Renderosity during the time that the item carried the exclusivity tag and was actually offered from DAZ, that person should track down exactly who did not carry through with their responsibility. The exclusivity tag acts as a notice to the buyer that the buyer does not have to do comparison shopping.