Choose the cap you have already unlocked.
The cap controls describe breakthrough stages, not your character’s current EXP level. If you already unlocked a cap of 40 and want 50, select 40 → 50. Selecting 30 would charge the earlier breakthrough again.
Keep the EXP bill separate.
Breakthrough and optional ability costs remain separate from the displayed EXP requirement. EXP uses the same level endpoints, starting at zero EXP; it converts the total to highest-tier guides, rounded up, without deducting owned EXP or items. Leveling coins are included in the total; completion time is not calculated.
Read the result as a shopping list, not a deficit.
We do not know what is in your bag. A total of five items means that the selected upgrades consume five—not that you need to obtain five more. Check what you own in the game before farming.