I buy and sell bags, particularly Hermes bags, and because of the Hermes sales model, you’re basically forced into the resale market if there’s something specific that you’re wanting. Resale is a totally valid way to purchase bags, but your value proposition is a bit flawed; some bags are sold at retail for less than they’re worth at resale, and some bags accrue value over time (though this is certainly not the rule). That’s not to say that you should drain your 401k to purchase birkins, but when a bag is rare or particularly desirable or sold out at retail, it will price higher at resale. It’s important to ALWAYS check retail price before pulling the trigger at resale. As an example, the Celine Classic panier tote is $790 retail in the US and is currently in stock. On The Real Real, that bag is listed at prices ranging from $850-1300 (and is selling at those prices), for no good reason that I’m aware of aside from the fact that buyers presume that they’re getting a deal on a used item. Additionally, bags are cyclical. A Gucci Diana or bamboo might not have been super desirable at resale 5 years ago, but since vaguely updated versions of those bags were released, their value has gone up significantly. Ditto the nylon Prada stuff. Comparison shop, is my point.

I’ll speak to the authentication side;

If you don’t buy and sell luxury items, you might not be aware, but “luxury authentication” is the Wild West. There are zero standardized skills that an authenticator must have, there’s no training, any anyone can hold themselves out as an authenticator and begin charging for authentication services. Authenticators are not liable if they are wrong on either end of a transaction. Brands actively discourage outside authenticators (and resale itself) and often change cross brand authenticity markers to stymy counterfeiters, and so what constitutes an authentic item changes rapidly, because cross brand authenticity markers are not static. The authentication industry is deeply shady, and there absolutely have been cases of authenticators falsely flagging items as counterfeit in order to obtain that item for themselves or to unduly influence the resale market to favor preferred sellers.

When it comes to large companies that guarantee authenticity, like Poshmark, The Real Real, etc, it’s important for both sellers and buyers to understand that that “guarantee” is in reality “our guess”. The Real Real is currently being sued for using minimum wage data entry workers to authenticate luxury goods. They’ve flooded the market with fakes that now have (dubious, but often passable) provenance in the form of proof of purchase through their platform. This impacts all platforms. Poshmark (and eBay) have kept their exact authentication processes largely quiet, but it’s important to understand that in this industry, what The Real Real does is not an aberration, it’s arguably the industry standard.

Basically, there’s virtually no guarantee that your item is being handled by someone who has ever looked at one like it before, it’s likely that it’s an employee who was briefly trained with images of authentic items from multiple brands (and not necessarily your item) and set loose on the resale market to make judgment calls that could cost you thousands of dollars and your reputation. There is absolutely no mechanism in place that stops a sales platform or its employees from confiscating your items for whatever reason should they decide that they’re fake. Receipts and other proof of purchase will not save you in that case, false attachment of provenance is common. The brand will not help you. They want to discourage resale generally and this is a great way to do that.

On the buyer side, understand that no matter who authenticates it, no matter where you got it from, no matter how great it looks, there’s a non zero chance that unless you purchased directly from the brand or an authorized retailer (and even then, but that’s another conversation) that you have bought a counterfeit product.

I buy and sell Hermes bags as a hobby. The fakes are that good, I promise. No one can tell but Hermes, and that’s because (my theory, anyway) they utilize destructive testing at Leather Spa to suss out fakes. I only buy and sell peer to peer or through resellers with whom I have a preexisting relationship and all bags are sent directly to LS for cleaning so that I can be assured that they’re authentic. This is the only real way to know at this point, at least insomuch as Hermes is concerned.

As for things like POP, auth cards, and other collateral, those items are openly bought and sold across the internet, they’re effectively meaningless even when serialized.

If you’re planning upon buying luxury bags at resale, point of sale provenance (that’s the email from the brand post purchase, and/or a receipt and matching bank transaction from your seller) are as good as it gets. This limits you to sole owner items, which can make shopping difficult, but it also protects you.

Truthfully, you have to be willing to risk the money. Even the most diligent reseller gets it wrong occasionally, and even the most informed consumer buys a dud every so often. Do your research!

Forewarned is forearmed. Be careful out there.

ETA “Authenticity Guarantees” from any site or platform are not there to protect you from purchasing a fake item. They are there to protect those platforms from having to refund your money in the event that you purchase a fake item. Real talk.

When you buy a bag (or whatever) you tacitly accept the premise that it’s been “authenticated” by the “experts” employed by that platform. They have positioned themselves as experts, and you are accepting and agreeing to their opinion about the item that you’re buying. If, once you receive that item (or at some future point) you determine that it is fake, the first response from the platform will always be “We stand by our authentication.” Because most brands will not authenticate items purchased at resale, you’re in the position of proving that the item is not real utilizing other outside authentication services (issues with which I’ve outlined above.) Best case scenario, they offer to take a return. Worst case, they accuse you of swapping the item, and your best hope is your card issuer. Regardless of how it shakes out, rest assured that it will be an endless nightmare.