User blog comment:Sethimothy/I Need Better Spheres... But What Can I Get Rid Of? (Video)/@comment-26148878-20161115193856

Item, just look in wiki what can craft with them and think what you can to craft (some things are useless or it could be too much work e.g. Melord's Core IMO)

Sphere that I sell in your case are: Just remember that some useless Arena spheres could be upgraded, by mix them with others, as happened like Hero Stone, these update is relatively new, so in a future could be added new update for other Arena spheres and keep them could be wise, at least one.
 * Earth Blade (just for collector) (useless even if was a non status boost sphere)
 * Hero Stone (just keep 1 for future craft)
 * Divine Stone (just keep 1 for future craft)
 * Muramasa
 * Angelic Foil (considering you already have Masamune's and Amano's)
 * Lizeria Gem
 * Limbo Stone
 * Sacred Jewel
 * Medula Gem
 * Legwand Gem (just keep 2 o 3 if you plan to craft more Malice)
 * Royal Bud (except if you plan to craft some of next spheres that required)
 * Magical Axe (easy craft again if need it)
 * Mix your Sol Creator and Luna Creator into Celgrand Gem (just 1 or 2 because there is not so usefull a this moment)
 * In general Drop type spheres are useless (all hard content have drop resistence/null)
 * Evil Shard ( considering you already have  Magic Ore, Fake Stone and Sacred Crystal if need it)
 * Star Blade (Arena Sphere)
 * Holy Crown
 * King's Crown (Arena Sphere)
 * Dragon Ring
 * Dragon Stud (Arena Sphere)
 * Soul Spear
 * Refined Gem (just keep 2 or 3, you already have some Cosmic Dust, Star of Hope and Twinkle Gem that are better)
 * Thunder Bow (unequipped first, Evil Halberd is better)
 * Blessed Robe (just keep 1 for future craft)
 * Glass Crown
 * Demon Lance & Hades Lance (Divine Spear is better)
 * Divine Spear (keep 5 is OK, for metal parade team)