Love is not all: it is not meat nor drink
Nor slumber nor a roof against the rain;
Nor yet a floating spar to men that sink
And rise and sink and rise and sink again;
Love can not fill the thickened lung with breath,
Nor clean the blood, nor set the fractured bone;
Yet many a man is making friends with death
Even as I speak, for lack of love alone.
It well may be that in a difficult hour,
Pinned down by pain and moaning for release,
Or nagged by want past resolution’s power,
I might be driven to sell your love for peace,
Or trade the memory of this night for food.
It well may be. I do not think I would.”
--Edna St. Vincent Millay, "Love is Not All (Sonnet XXX)",
from Collected Poems: Millay, Edna St. Vincent (1956).
So, to sum up:
She liked the guy?
Could not give you a better answer than this:
When I read it that's how I interpreted it until the final line, when she seems to revert back to the standard "love conquers all."
Probably, she is saying: If I were starving or in severe pain, I might sell your love in exchange for food or to relieve my pain. I don't think I would, but I might because love isn't everything. So, love isn't everything, but it's so precious that I would not sell it. I could, but I wouldn't.
I read it this way. Not sure if this is what she intended when she wrote the poem.
We'll never know for sure, and that's good.