Everyone needs to assess their own situation. You should have an idea of whether or not it's reasonable for an MPA to 'like' you. For example, 1) are you the type that had no problems dating civie girls, 2) if you did not meet the MPA at the spa, would it be reasonable for her to like you (i.e. is she out of your league), 3) if it's not money, why else might she be attracted to you (physical, emotional, fun), 4) do you have common interests, background, culture, 5) is it easy for you to get close to other MPAs, do you make them laugh 6) what are signs that she might enjoy your company, hint: her spending significant time with you outside the spa with no money involved is normally a good indication, etc. etc.
For me personally, when I ask myself these questions (and more), I do not find it 'unreasonable' at all that some MPAs might like me, mostly the 40+ ones but even a few in their 30s. Now, if I ask the same questions with regards to a young, attractive MPA in her 20s that lives a full life with many friends her own age, then yeah, my thesis would not hold water.