Here is an interesting bit of information: Some e-commerce site owners are seemingly under the impression that they can disclaim liability for their sale and offering for sale of trademark infringing and/or counterfeit goods. Online market place operators, such as eBay, may escape liability in certain instances; as indicated in the Tiffany v. eBay case in 2008, a New York Federal Court ruled that eBay’s efforts to remove individual sellers of counterfeit goods were sufficient to shield the online marketplace from liability. But individually owned e-commerce sites - as distinct from online marketplaces that consist of third-party sellers - run a bit differently. Sellers are responsible for the items they sell and disclaimers (e.g., "I cannot guarantee the authenticity of this item") usually have no legal effect and do not protect the seller from civil or criminal liability.
First things first: What is a trademark? Put simply, it is a name, logo, symbol, etc. used by a company to identify its goods or services. Trademark laws are designed to aid consumers in easily identifying the source of goods or services, and to protect consumers from confusing one company's goods or services with those of another. A general guideline that eBay shares with its users to assist them in identifying trademark infringement is this: "If the product you are selling [or buying] bears the name or logo of a company, but it wasn't made, authorized OR endorsed by that company, it most likely is an infringement to sell it."
eBay also provides some useful examples of trademark infringing goods: "A purse that has the Chanel name on it, but which was not made by Chanel; sunglasses bearing the Oakley name, but which are a style never made by Oakley; an internet domain name or member name that contains in it the trademarked name of another company (e.g., www.disneymovies.com); a listing that uses the logo of a company in such a way that it looks like the item came from that company, when it did not."
As indicated above, repeatedly disclaiming knowledge of or responsibility for the authenticity (and thus, the legality) of items that you are offering for sale is not a valid defense in court. It is pretty clear across the board that Louis Vuitton items do not retail for $25 and they are also not made in China. So, do your research in order to avoid offering trademark infringing goods for sale because you very well may be liable.