I imagine geting prestige 10 will take around 4k hours total, assuming you're good at it.
I also thought about making my entire collection shiny, but first I need to complete it. I was quite sure I will be able to get all cards after this massive scrap fest, but still Gwent has so many cards I am missing over 20 legendaries.
After 18 months (almost to the day) I have finally reached Prestige 10 and it was my time to do some 'Smash Smash'
I'd been hoarding barrels for several months (from around Prestige 6 or 7) and collected 1130 of them
Apparently, you can mill only 3000 cards in one go, that's why there are two notifications.
I have also made nice progress in my 'Some People Just Like To Watch The World Burn' contract. If I keep my current pace and don't die of clogged arteries, I should have it in my pocket on Tuesday, 5 December 2028. Parit patientia palmam