There were a couple of items I wanted and intended buying from the UK but they didn't supply one of the items to Greece. I looked on the German site and both could be delivered here: one of the items was cheaper than Amazon UK and shipping was slightly less. I just opened an account with Amazon.de, ordered what I wanted and they sent them quite quickly. Also, I was able to use my Greek Credit card so wasn't concerned about exchange rates.
Inevitably there will be some things they can't ship here because of some manufacturers' exclusive distribution agreements with some suppliers.
Now, before I order anything except (Kindle) books from Amazon UK, I always check prices and availability with the German branch. There's an English language option which is pretty good despite a fed add spellings and the occasional description that reads like a 'Google Translate' effort but on the whole it works OK.