I'm worried about the 128GB more than the i3. And moving to 256 costs you $200. That's just insane. An i3/256/8, no dGPU, headless computer is $1000. Education discount saves you just $40 not hat model. I've used Apple computers for decades now, but this is maybe the most shocking price hike I can remember.
It's a modular system with the ports it has. Buy an external drive for cheap and add as much storage as you want. It's not hard.