Interconnected

How to swap Amazon gift cards for cash?

So for one reason or another, I have several hundred dollars of Amazon.com gift cards. Accumulated over the past few years. The thing is, I don't buy anything from Amazon.com because I live in the UK, and the gift cards aren't transferrable between stores.

But now I'd like to get the cash equivalent. Somehow. There's something I'd like to buy from a US shop which has about the same value; it's not on Amazon.

I've never redeemed the gift codes, so it's easy to send them to someone who can use them. They're all still valid. Online gift card exchange sites are US-only, and expensive. Maybe I can find a person could buy from the other shop for me? But that's a big exercise in trust, so I guess I could take a dollar-sterling transaction forex hit. But even then, how will I even find someone who buys that much from Amazon.

Dunno. Any ideas? Any friends able to help?