Usually when Next Out of latest is champed, I’ll do Classic till they drop out. Sometimes like this batch, I’ll champ the second out first and have to keep after Latest. So Elektra got an extra 6 covers that would have been nice on another character, but whatever, she isn’t too bad. I’m debating on holding on to cp once Abigail drops out since I have such a poor showing on Crystal but I tend to get bored pulling nothing for that long.
Just track the number of LTs and CPs you earn once per week for the next 4 week, and you'll have a rough idea of whether you have excess cp to pull for Classics. With this knowledge, no wild guessing is involved. I'm not sure how your roster looks like but his 4* roster is pretty matured, I think.
I do seem to have a big spender in my alliance, but i have the attribution on who it is hidden. So there is a probably not insignificant amount of CP coming in from that. But I myself am and have always been completely F2P
So far I've been able to keep up with baby champing all LL using LT and CP earned monthly. I complete CL10 PvE for progression, and CL10 PvP to the 10 CP mark. That hasn't left me anything extra to go after classics, but one month I did burn my CP on the Crystal store because it had two classics that I hadn't champed yet. I probably can't do that every month, but it looks like I'll get it away with it this one time. Currently at 28 LT & 912 CP. I thought I was approaching the ISO hump, but lack of ISO continues to be an issue. I've stopped leveling new 4-stars to ensure that I've got ISO for champed 5-stars.