>>58250867If you have the premium pass, then you should be buying your seeds from the premium shop whenever available, but if you don't, then trading in for a Main Skill Seed or Master Biscuit is up to your discretion. 4,000 Sleep Points is a LOT. That's just short of an entire month's worth of 100-point sleeps (including Good Sleep nights) for a non-premium player.
Most single-stagers really aren't that great either, and spending your month's worth of points on a single Master Biscuit vs 30 Poke Biscuits isn't a very wise use of your resources. You should really only use them on Legendary Pokemon, since you only ever see them once in a blue moon anyways.
And while I don't think it's necessary to buy Main Skill Seeds from the regular exchange shop as a non-premium user, they're very valuable for a lot of the strongest Pokemon in the game. Aside from E4E, you have the dogs, Cressalia, Darkrai, some of the Charge Strength Pokemon, Berry Burst Pokemon, Dedenne, and whatever other skills you feel like messing around with, like Metronome.
