Based on what I've read, I don't think Olga cared two jots for Boris--at least romantically--and doubt she would have cared even if he'd stood to inherit the wealth of, say, a Felix Yussovpov.
Review the men Olga was attracted to and you'll note they were not especially wealthy. But they do appear to have been men of character. I don't think it was the discrepency in age that would have bothered Olga re: Boris, nor the gradual atrophy of his former good looks that was in process even just before the war. But he did have an exceptionally shady history--even for a grand duke--and his accomplishments were far more dubious than celebrated. Add to the mix a potential mother-in-law who could match Alexandra (and then some) in manipulation. Not to mention a couple of brother-in-laws with their own ethical baggage as well.
Olga wasn't typically sweet and amiable like her sister Marie, nor did she toe the "political correctness" line as did her sister Tatiana. And since I am non-Orthodox, I do not regard her as a saint. But it appears she did have considerable strength of character, especially when it came to determining her life via the royal marriage market. My guess is had the revolution not occurred Olga ultimately would have accepted betrothal to a prince within Russia--or very close to Russia--whose moral character was a close if not absolute match to hers. (That eliminates Prince Carol, and Grand Duke Dmitri as well, unless his direction had reversed itself.) And if Olga and her family had somehow survived the Revolution as exiles, I think she would have followed the lead of her Aunt Olga and married according to her heart.
