Allow me to share what I think and what I usually would do.
Encompass is the main carrier of Sony parts, and if they don’t have it here in the NA, no one will do. There is no need to source them anywhere else. Sony parts are very easily obtained. If there were anything ever wrong with the Walkman, such as batteries, connectors, internal wires, antennas, screen cracks….etc, I can always take care of them, if the $$ was paid to me rather than buying Allstate insurances whom don’t even know what you are talking about lol!!!
I, myself, dislike insurance claims generally, even when buying new cars, or appliances, they are just horrible all around. The only one I would pay additional insurance to is the local hardware store where I personally know them that they sell warranty by themselves and hire local workforces with proper trainings and properly equipped with different personnel and different dedications. It had been here locally owned for more than 3 generations and whenever there is something wrong, they always take good care of their own stuff that they sold.
For all that said the way I look at what you described and if I was in your shoes, I would have saved that $520, and if something happened down the road, I would take into account of depreciation and add more $ to buy the next device. Assuming the deal for 1Z was $2800. Your insurance costed 18.5%.
Now, if something was to happen to it, you would need to pick up the phone, call around and waiting about, get transferred, waiting for call back…etc…waiting for approval…seeing what they can do to reimburse you. In case that they could and would sent it for repair, you would need to wait around for shipping, then waiting some more, and if it ended up “non fixable due to parts availability” then you would need to wait for a new device sending to you. How long are all of those waiting, phone calling…etc…is worth it to a person ? I have no clues, but I personally hate it when I have to deal with it.
So, when sheets hit the fan, I rather pay out of my pocket, within %20 and ask for a known person, service place, to work on my stuff. If not, I would just take that was my “luck” and so I would just use that 20% + some more and buy new product. (Depreciation + my luck + new device) usually worth it in the end lol.
Back to this high gain stuff, why the Japan devices has no restrains ? But the rest of the world ? What in the blue sky ? If that was what it would be, people would be just buying from Amazon Japan, import it ? Also, I would think Amazon warranty would be worth it, because they sell all kinds of stuff and is almost a world monopoly, if something happened, they would either refund 100% or replace to new device with no questions asked. That is what I would think ? But then again, as I mentioned above