Hello, dearest DJ... and peace to you!
What we have to remember is that all of the accounts were written some time after the actual events, none of them were "inspired", and so there has to be some leeway for errors in recollection... as well as in "belief" (i.e., one writer may have thought that the feet were of no significance, where another thought ALL of the details should be included).
Please also note that while the Bible accounts most assuredly give evidence that it was Mary the sister of Lazarus who was the "sinner" that washed my Lord's feet with her tears, dried them with her hair and then oiled them, there is no point-blank indication that this "sinner" was Mary the Magdalene. Contrary to what the WTBTS and "christendom" in general teach, Mary the Magdalene is not directly named a "sinner" or prostitute, as most seem to think (even I did!).
The connection truly can only be made by the fact that Mary the Magdalene was among the women (called so in one place - Luke 8:1-3)... and harlots (called so in another, but I can't recall right at this moment)... who went "before" my Lord on his journey from Galilee to Judea, as well as the fact that it was Mary the sister of Lazarus, the "sinner", who poured expensive perfurmed oil on my Lord's head and feet... and that it was Mary the Magdalene who brought expensive perfurmed oil to prepare his body after his death... along with Mary the mother of my Lord... and there were only two (2) Marys present at that event (there was a third Mary, the wife of Clopas; the Society, however, has a fourth Mary, by separating out Mary Magdalene from Lazaus' sister, Mary).
With regard to the expensive perfurmed oil, logically we can know that most "regular" women would not have had such oil, at least not in an amount to do what "Mary" did. True, one may have possessed some as part of a dowry or inheritance, but she would have used it sparingly. Only a woman of means... or a woman of ill-means... would be able to afford such oil, and abundantly so that she had enough to anoint him on his head, grease his feet AND prepare his body for burial. However, a woman of "ill" means would also likely to have some such oil, most likely either receiving some in payment for services, or purchasing it for use in her "trade".
I know that this sounds a bit "like" the WTBTS' way of explaining things, which I abhor because it is always so unsubstantiated but based purely on speculation... so I am trusting that my Lord will grant my brothers and I even more substantiation, as I although I believe that what my Lord has told me, that which I have "heard" from him... that Mary the sister of Lazarus and Mary the Magdalene are one and the same... it is for the sake of others who might need a little more "proof" in order to exercise faith in "the thing heard." If it IS needed, he will provide it; he always does.
I hope this helps...
Again, I bid you peace,
A slave of Christ,