Am I writing a duology or a standalone?

I’m currently almost done with what started as a standalone, morphed into a duology, and now looks like it’s morphing back into a standalone…. I’m not sure which direction to go in editing.

The genre is adult fantasy. Book 1 is 70k—a bit short, but my novels usually gain a little in editing. Book 2 is a few chapters from done… and it’s going to be about 40-45k. There’s no other good point to divide the two books… so now I’m wondering if I should just recombine them into one novel. (Structurally, it could go either way.)

The disadvantage is that I’ll be making half the amount of money (not to be totally mercenary, but that’s just the reality) if I combine them. I could charge slightly more for a 120k word book… but not twice as much.

The advantage is that I’m currently in college, and long-term publishing plans are really challenging right now because I don’t know what my life will look like in a few years. So publishing a standalone novel is just easier than trying to plan for two book launches and so forth. (And it’s also cheaper and easier to just have one cover and one round of editing, instead of going through that process twice.)

From a marketing/publishing perspective, which makes more sense? I’ve published two books before (indie), but never a series… and so I don’t really have that past experience to compare this to.