The idea behind most "low fantasy" (or "low magic" or "magic rare") systems is not simply to "nerf" magic and make it less fun to play a wizard; it's to create a consistent system that doesn't lead to a world full of magic shops, wizards-for-hire casting dozens of spells per day, etc. The goal is to create a world more like Howard's Hyborea, where magic isn't routine or mundane -- but where it's plenty exciting.I just dont like it when you have to do an hour ritual to just cast <I>Magic Missile</I>, and then have to roll a spellcraft check, and if you fail take 2d4 permanent con damage, and lose the ability to cast spells for the rest of your life.
If the example above (with a long ritual and a Spellcraft check to avoid Con damage, loss of magic abilities, etc.) is supposed to represent a magic-rare game, I think you missed something: the spell to be cast would be powerful and risky, rather than weak and reliable. It would summon a demon or rain death down upon an army.