Alternate magic system for D&D/OSR Clones/Etc?

All the twists to magic in systems like DCCRPG, Lamentations of the Flame Princess, OSR blogs, and on G+ has got me thinking about designing an alternate system, using numbers from the book, that is both functional and easy to extrapolate from existing rules. If one of the reasons OSR folks enjoy older systems is that non-magic classes don't have defined 'moves', and thus players are encouraged to be creative in thinking of their own, why shouldn't there be a system that opens up this freedom for Magic-Users?
This is just going off the top of my head at the moment.
My thoughts currently look like some weird point buy system, where the points after level 1 are determined by the spells/level charts in class descriptions.
So 1 point per level, and 1 point per spell slot and level on the chart in the PHB. (So a 3rd level Mentzer Magic User would have 7 points: 1 for each level, 1 for each of his 2 first level spell slots, and 2 for his second level spell slot). A first level Magic-User would have 2 points (1 for his level, 1 for his First level spell slot).
No pre-written spells. Slots become points. What do you do with the points?
- Points put towards a spell can add either an effect, an area, or a target.

- Effects: effects cost 1 point per effect per target. Parts of the body count as 1 target each. Effects that cause damage cost 1 point per d4 per target. Effects that cause damage are visible and clearly caused by the caster unless 2 points per d4 of damage are spent to disguise it. Illusions are tricky; the original must be erased before a falsehood can be constructed - making something invisible is 1 pt, making something look like something it's not is 2 points (per target).

- Area: 1 point per 5 feet (or whatever your basic square/unit of area for spells is). Spells affecting targets the cast can see can ignore area in favor of specific targets.

-Targets: 1 point per target. Living things count as 1 target for general damage, and 2 for illusion effects (upper body, lower body). It takes 2 points total (1/effect, 1/target) to damage someone, 3 (1/effect, 2/target) to make them invisible, 4 (2/effect, 2/target) to disguise them. (Called shots can be helped along with point expenditure = spend 2 points to hit your called area on a 19 OR 20, instead of just 20).

Replicating the effects of Magic Missile takes 2 points - 1 target, 1d4 of damage. However, the player gets to describe it however they want without being influenced by the words "Magic Missile"

Replicating Sleep is more tricky - 1 target or 5" is 2 points, etc.

Point burn is possible - extra points can be bought with ill effects. For every point beyond what the Magic User actually has that his/her player wants to put towards a spell or effect, the more likely there is to be a fumble or random effect (or maybe just 1 random detrimental effect per extra point?)

I think it provides a reliable base of spells but the point burn adds a whole field of temptation akin to the corrupting effects of magic many of these OSR clones are trying to get at. A magic-user can be boring ol reliable and do a few things, or more powerful but with more risk.


I'll keep thinking about it, and would be delighted to hear input.

(edited to make illusion stuff clearer.)