Exchange Vita and Mana is based on Base Stats
Base Vita/Mana is your base without any other stats
You can check your base stats from F1 -> Character Info

The maximum vita shown in the Status while naked is
Base Vita + (Might * 25) + (Grace * 15) + (Will * 5)
The sama on Maxium Mana
Base Mana + (Will * 25) + (Grace * 15) + (Might * 5)

If all of you think the addition of Vita and Mana from the Might Grace and Will is very confusing, I will be very happy to remove it in the next update. Just let me know.

The Sunset Exchange ONLY add your base stats
the very same also will be applied to Might Grace and Will exchange in near future.

Thanks.