What is this "enough" you speak of?
While it's obviously a personal choice for everyone, I'm in the camp that assumes electronics will go bad. I am estimating that any given non-mech mod will last at best 2 years. So since I believe you said you had 4 Picos also, you have at most 14 years before your last regulated mod dies in my estimation. That's my way of thinking and part of how I decide if I have enough.
I didn't give a mech 2 years life expectancy. I planned on scrapping a mod every 6 months. Things are so much cheaper that I don't care how many they bury me with, better that than to run out.