+%SpellCrit = 2600
+AllSpells = 192
So +1% spell crit is worth about the same as 2600 / 192 = +13.5 spell damage (an item with +1% spell crit could have +13.5 spell damage instead, for the same amount of "item points").
My fireballs (with +300 spell damage) hit for about 1000 damage. My crits do 210% damage due to the Ignite talent. That means with 1% extra crit I will do 1100 extra damage over 100 fireballs, so +11 damage per fireball.
Without spell damage, the numbers would be (1470 - 700) / 100 = +7.7 spell damage for 1% spell crit. Even lower than before.
Seems to me that +crit is valued too high - even with +300 spell damage 1% spell crit is less than +13.5 extra spell damage.... Of course you could also argue that +spell damage is valued too low, which Blizzard will probably discover before 1.9, resulting in a big nerf of all +spell damage items. Hurray!