Well, yeah, my objection does take it into account, but I was being unfair in my implicit assumptions because I didn't think it likely that anyone here would object.

If you're to end up wanting it, and that you'll end up wanting it enough to compensate for the opportunity costs regarding other things (...)

Basically, this is where I lumped an implicit: "For most humans, the desire and expected benefits of successfully entering a relationship are much greater in terms of evolved values than the opportunity costs incurred, and it is reasonable to expect that the gains obtained from this would free up enough mental resources to actually make faster, rather than slower, progress on other goals of interest in the case of well-motivated individuals with above-average instrumental rationality."

However, estimating the costs you mentioned for humans-on-average is difficult for me, due to lack of data. Picture me as wearing a "typical mind fallacy warning!" badge on this particular issue.