Independent retailers are getting squeezed out as suppliers, factories and freight companies prioritize national brands. In many cases, they’re losing out to giants like Walmart and Amazon, which are spending millions to charter their own ships and planes to move merchandise. Independent shop owners, who have no such recourse, say they’re often the last in line for products because manufacturers prioritize larger, more lucrative contracts. Even without their own ships, major chains like Walmart — which last year imported 900,000 containers of goods — have long-standing contracts that guarantee low prices for ocean freight. That leaves smaller importers to compete with one another for “spot rates,” which have jumped from $4,000 per container to about $24,000 in the past year.