Let me explain a bit more thoroughly. There wouldn't be a currency spending limit per character, because that is much too complicated. So we would decide as staff on a common ground for the stats. In a hypothetical situation, primary stats could be limited at 1m each, then secondary stats like AP and SP could be capped at 2m. Anyone who is currently over the limits would be reimbursed per stat per character with a different stat or different custom items, but the staff would have to discuss this more carefully if this happens to be the outcome. These limits are just hypothetical at this point, but we could implement a cap based on the general population's average stats in each field, or figure another way to compute it. Devs and Admins wouldn't be affected by this kind of ruling, but new rules would be added for us that would disallow the use of over-capped characters in PvP.
If we reduced the stats by a percentage, we would also reduce the stats you can purchase per dollar amount. In other words, the value of the stats remain unchanged if we were to reduce by some percentage. This would in no way effect value of the stats you may purchase, simply a server-wide nerf. Say we reduce by 30%, that 30% reduces my resistances by 30%, and the amount you can purchase per dollar by 30%. So here is a math example: 1000 resists is reduced to 700 resists, and the value of resists is at 100 per $1, which would be reduced to 70 per $1. The value remains unchanged.
Yes, this is essentially similar to Reaper's Stat-Slash.