I will say that 128GB could easily feel too constrained rather quickly.
Throw in a medium sized iPhoto/aperture library, a sizable iTunes library and all of sudden its too small. Data, applications, and operating systems are not getting slimmer but more bloated. The 256GB gives you room to grow.
So for your own future proofing 256gb is not a bad idea, regardless of potential resale value
Correct. A computer is an expense, not an investment. Buy it for its merits while you own it, not the day you get rid of it.IMO, it's a bad idea to buy any computer based on what you think the resale value might be.