Of course, you still have to play the game for the time until you get that 100 Enchanting and learn the appropriate enchants. So if the perks help you during that time, they probably are good investments. (unless, of course, you do something silly like powerleveling your Enchanting before you really start playing the game )
You make me feel guilty
I admit that's what i do since i find enchanting so annoying , i always powerlevel it before "enjoying" the game properly and wearing "my precious" enchanted ring and clothes in combat
Regen in combat is bugged or nerfed so badly that it's not worth it. Out of combat regen is fast even without any enchants or perks. In combat is too slow even with enchants and perks. So they are useless.
Better to get the reduction to the school and + magicka (since you get back a % of your total pool increasing your pool increases your regen rate too) and chugging a potion now and again if you need to which is instant mana regen. Not like potions are hard to come by or make.
I never understood how people do this, I still only get like 5% reduction, do you just start enchanting at lvl one and not stop or level up until its high enough?
If you're willing to get Enchanting to 100, put eight perks into it and permanently "sacrifice" four of your apparel to do nothing but reduce casting cost... sure.
For a battle mage you might have a point, but for a mage what else are they putting there? Resists are about the only thing worthwhile for a mage and even those are not that great given all the ways to cap them. And with 8 perks you can fully handle a school and still have 4 enchants on those items for other things.