The other person covered most of it, but also, I'm at about 20 hours, only level 9, have mostly done solo level 1s with some 2s and a handful of missions with friends.

I'm around halfway through the first warbond and between what you can get in it and from missions, I have about 1200 super credits, at least 600 of which I got in mission.

(Edit to add: 5 to 10 per mission? You'll find multiple pickups of SC most missions and each one gives something like 10 so that's nowhere near accurate)

It is absolutely farmable. I know several people who've unlocked multiple premium warbonds without paying a dime, under level 30 and not no-lifeing it.

On top of that, nothing in the premium warbonds are significantly better than everything in the base warbond. You could never bother touching the premium warbonds and do perfectly fine.

Plus, these are not micro transactions. They're not pay to win, they're not predatory expendable items to boost a mission or something like that. If anything, they're micro DLC that you can fairly easily unlock just by playing.

I wonder if you've even been playing the game at this point because these are all things you'll figure out pretty quickly if you do.

Edit to add: I see someone responded and deleted their reply but it was something about how the other warbonds only give 30 SC each. That is completely inaccurate, they each give 300, with 100 in each unlock. This is incredibly easy to verify, all you have to do is log in, open the warbonds, and look. As for the rate of acquiring them otherwise, I refer to how long I've played and how many SC I've gotten in that time of very casual play. Just logged in to check and it's at 1160 SC, 550 of which is from warbond unlocks. So, no. It's not particularly grindy.