I have 2 daughters both married and living in a different city/country than I do. I am on my own. We all struggle financially. I would like to ease their burden by planning and paying for my levayah (funeral). I can do this through the local funeral home who has a plan with an insurance company and by paying it out with small amounts over a number of years. I shared this with a close friend who felt that I am taking the mitzvah from my children of attending to this need as a final mitzvah that cannot be repaid. Of course they would still attend to the all my final needs but will not have the costs to worry about. Is there an issue with what I am planning to do?
What you are doing is fine, and it doesn’t deprive your children of any mitzvah.
As you rightly note, the mitzvah is to take care of all the needs of the deceased, and not necessarily to pay for the burial and related costs. Of course, after your 120 your children will be taking care of everything, and your paying for the levayah will surely not take away any mitzvah.
Best wishes, ad 120 shanah.