It's credits, I'm not sure if it factors in the value of the stash, but you lose all that anyway. Keep in mind it was $1m increments last time, up to $5m. Each million got you a skill point and a few extra inventory slots. There's no telling what the requirement will be for the second reset yet, I suspect it might be a bit more or even double.
It doesn't reset any of the other items. You lose stash, skill points reset, quests, benches, and blueprints. There are many requests for raiders to be able to hold on to one blueprint each reset, dunno if that's gained any traction though.