Why should a Wizard wait for nine experience levels just to create a wand because they cannot cast twenty magic missiles in a day from first level? Artefacts come to mind as a reusable power investment by immortals, and the vaguaries of sentient swords suggest these are immortals in artefact form. So why not something useful? A hundred thousand experience points are required to invest a mere 10pp required to produce a first level wizard spell in an artefact that recharges in turns, not daily.
So lets suggest that entities with power are quite capable of investing their power in turning wizards into living Artefacts so that even the Apprentice magicuser Shaan can make a sacrifice and gain more power. Now your magicuser can do the bidding of some enthropic immortal, betraying the old wizard who has taken forever to teach you how to cast read magic.
Your Magicuser, in pouring through old texts, discovers that taking Religion as a Skill allows you to gain the attention of dark immortals quite capable of investing real power in your apprentice magicuser, but it comes at a cost.
From first level you can gain ten first level spell slots but they come with a handicap and a penalty from the artifacts creation section of the D&D Master black boxed set. You can wind up with physical deformities or any other burden, but its worth it for powers that can recharge in hours.
Spell level slots 10
You pray to demogorgon for an investment of power in you...and your spine begins to deform.