Some things could be considered broken without clarifications:
Pearls of Power: extreme case, buy or craft about 30 pearls of power for level 1. Starting at level 5 when you get word burning the fun starts.
A wizard burns a levle 3 slot and uses the points to prepare a 15 points spell. Once cast recycle the spell with a pearl of power.
Once per day on command, a pearl of power enables the possessor to recall any one spell that she had prepared and then cast that day. The spell is then prepared again, just as if it had not been cast.
http://www.d20pfsrd.com/extras/collaborators/work-area/minor-wondrous-items /pearl-of-power
With a higher level and maybe the urpgrade to level 2 pearls it could become a bit to effective:
Level 17 Wizard burns a level 9 slot, add it all to one of your level 2 spells slots ... thats a 39 point spell.
It could be:
Mass 2 Points
Frost Fingers 7
Shock Arc 5
Burning Flash (Boosted) 7
Force Bolt 4
= thats just 25 points.
Thats 5d4 force damage, 5d6 fire damage, 5d4 electricity damage, 5d6 cold damage and staggered for 1 round. To up to 17 targets. Ref save 12+casting stat.
Thats a level 2 spell, you can recycle them with level 2 pearls. Add a lesser metamagic rod intensified for only 3000 gold.
The example above could be made more effective with a level 3 or 4 slot - the magic to improve and reclaim the slot becomes more expensive.
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Another very effective option is a spell storing weapon:
Our wordcasting magus has taken notes from the stuff the wizard tried to pull. Say its our magus is level level 10 and burns his single level 4 slot.
Before every combat he can refill his (t)rusty blade with:
Target:Single 0 pts.
Effect Words:
Lightning Blast 7
Fire Blast 8
Frost Fingers 7
Thats at level 10 (and this spell won´t get any better) DC 13 + casting stat ref save, 10d6 fire damage, 10d6 electricity damage, 5d6 frost damage and staggered.
for 9,000 gp per charge.
This spell would be very good when stored in a weapon, it´s deadly when used in a spellstrike with say a keen scimitar.
Well I said my bit. ^^