Caleb myth?

Guys im a new player and im saving for Sylus's myth to drop but i really wanna get Caleb too now... i have plenty of diamonds but idk if it will last me for Sylus after i get Caleb. Any advice pls? I have 21015 dias rn😆 i spent 1500 yesterday to try to get Rafayels rerun but it didn't work out