[mytoraccount]

Will amazon ask the courier what happened on orders around 300€? And 800€?

no they will not as long as you are not required a signature. Usually amazon starting to require a signature at the 1000$ mark. Signature does not mean end of the world, you can make a story if thats your first SE or two in many orders between. Amazon representatives usually not bother to scroll your order history to see how many signature required package are lost. I se'ed a lulzbot taz6 worth something like 2500$ with a signature required delivery by fedex with no problem at all. Don't be shady in telling stories, think yourself like a normal peasant buying Samsung tablet or other Christmas gifts and need them before Christmas, always think twice before click the send button on the chat.