People trade in them as a kind of currency, so they could sell something valuable for 100 NMT or higher. Or sell a villager. Back in the day, Raymond was going for 400 NMT online.
I once sold a Valiant Statue for 80 NMT on Nookazon and then used the 80 NMT to buy a rare seasonal recipe, maybe Mush Lamp.
Some folks with older switches can also hack the game, but there are ways to get a lot of tickets through trade.