Read the fine print before buying. There are rules to purchasing liquidation. Each liquidator may carry a different set of rules or “Terms of Purchase”. Some may require that you do not sell within a certain distance of the original retailer, others may not allow sales in the US. Most require that you remove any retailer labels or information if on packaging and you do not state their name in your listing. Most of the larger liquidators will require proof of a “Resale Certificate”, this is highly recommended but not always necessary. It is important that you review the terms before making a purchase.
Lastly, it is important to buy products from as close to the retailer as possible. Every time inventory changes hands there is a premium added to the cost. I typically do not buy from second and third-party liquidators because the product has typically been processed at least once and premium and/or new items could be cherry-picked for that companies own private sale or advertised accordingly driving a higher value.