When you are attracted to someone in a relationship, there is always something you see in that person that makes you to love him/her. It might be character, good behaviour, physical appearance, responsible personality, money, social class, good family background etc, or even a hope of the person attaining one of these things in the future. So to me, these things are the currency with which that love is bought. So far you have a spec, those qualities you look out for are your conditions for falling in love.
Let me also back this up with family love. Often times when a child behaves well, he is loved and cherished by his parents and the entire family. But when he derails from this good path, you see some parents hate that child to the point that they lay curses on him. So here it's obvious that the condition for the family love the child enjoyed was his good behavior. Even in the bible, Esau and Jacob were loved differently because Jacob was a more loyal child. So can we still say that love is unconditional?
Also in a relationship, no matter how a wife loves her husband, once the man becomes irresponsible, that love declines and might degenerate to fights and quarrels. So here, the love was dependent on the respect and the responsibility the man portrayed. So I feel that as long as we have a choice to make of who to love or who to marry, those factors that influence our choices are the conditions for our love. I have heard people say I want to marry a nurse, I want to marry a tall lady or dark guy or from this tribe or the other tribe. These are all conditions for love and I don't think there is any attraction/love that does not have any of these.
So in summary to the question of if money can buy love, I will say yes, money can buy love and the amount needed to purchase the love is any amount that can make him or her comfortable and provide basic life needs. Likewise respect, good character, appealing personality, physical appearance, religious belief, social status etc can also buy love. I am yet to see any love that is not bought with any of these currencies . All we advocate for is for people to choose values that last, rather than money which may disappear tomorrow. The only unconditional love I am sure of is divine love. Because God is perfect. We humans are not perfect.
Please kindly share your thoughts on this, does unconditional love really exist?