The most I've ever had at once was probably around 300. That's when I was living with my parents and it was hard to order them without them noticing. So I'd wait until they went away for a few days and order enough to last a year or two as I'd never know when I'd get the next chance!
I'm probably down to about 50 now, although half of those are plastic-backed Abena M3s and Tena Slips which are in my "archive" as I don't think they make them any more. Hmmm... probably time to stock up again soon...
I have 7 unopened boxes with 3 packs of Abri Form L4 inside each, then a box of Forma Care, about 6 packs of Gompels diapers (Rubbish, will be binning them) and a verity of loose packs such as Tena Ultima, Fluffsan Night, Vlesia slip, Seni slip, AMD Slip, must be close to 1000 diapers on hand.
How the hell did you manage to hide 300 nappies?