The Netgear NAS (diskless) costs 729€, so they ask 370€ for the 6 disks, which is 61.50€/disk, quite the same than if I would order them seperately.
Today I just copied something to my NAS, and shortly after my modem again restarted twice, don't really know what the problem is. I don't also have the time to test this now, leaving the NAS on/off then see if it happens again. Tonight when I come home I will check the event log of my modem, then I will see if it restarted again or not, although you only see the last time it logged in, you don't see if it did it only once or 10 times.