Yes, I had spotted this, although they are based in Guernsey, not Jersey & the prices do differ, so is it the same company and the restriction to UK only delivery could be the reason for lower costs or just the same web developer? After all the Tesco site is very close to the Amazon one, in looks - but I wouldn't assume they are the same company.
I've used them quite a bit. They are OK for 'In Stock' items, but back orders and new releases can be slow being shipped. Don't take any notice of the 'Ships in 3-5 days' etc - it could be 3-5 weeks or never! They don't charge your card though, before stuff ships, and it's dead easy to cancel orders on the website. They do, also, answer e-mails. Oh, and their shop is in Eastbourne!