Long story short, my 169 Mercedes is in dire need of skill books, only having Dual Bowgun Expert maxed from the special skillbook given back when she first launched. Everything else has only 10 SP. (Except Lightning Edge which I am skipping altogether, and Rolling Moonsault which doesn't need a skill book, thank god.)
But..... that Tempest Set would actually be a significant upgrade for her. Even the pieces that wouldn't be a direct upgrade (Weapon.) would be so after the set bonuses. And it's not like I'll ever be able to afford the Empress Set, let alone beat them out of Cygnus herself.
So where should I invest my coins? Into Mercedes Skill Books, or into the Tempest Set?