Most Nike items will follow this rule if it contains the small serial code label. Look underneath the wash tag to find this reference.

All authentic Nike shoes have a tag sewn into them with their size, barcode and model number on it. You will recognize it most easily by the barcode. Look for it inside: The tongue.

Conclusion. What drives the retail markup for the Air Max shoes up is the demand by consumers. Thanks to the influence of technology, comfort, design, style, and hype, many sneakerheads cop Air Max sneakers, and thus, due to demand and supply chain, the sneakers are more expensive.