Sponsoring the children

I donate to a scholarship where I can sponsor the students I specifically pick (all applications are from the same university). It costs me around $10k/student/year (I sponsor two) and mainly this provides a partial stipend, but the schools appreciate the private money so much the university fills in the rest if the stipend and covers tuition/fees/etc. I had this when I was in grad school so it's only right that I give back.  If the student has a fellowship already then this money goes on top of that.  Pretty awesome.  I pick my students based on what kind of research they do and then their personal/professional essays.  I've met some great people this way.  There's a big ceremony where the students get their awards and get to meet their sponsors.  It's a lot of fun to take part in as a student, and just as fun as a sponsor.

I really enjoy this because I get to see some of the state-of-the-art, talk with interesting people that really care about research, and get a couple nice dinners.  At the most recent dinner I started to realize that I may not be able to take part as much for a couple reasons next year.  First, I'll have less disposable income.  Second, I'm concerned about the conflict-of-interest.  Is funding a different PI's student at a competing university ethical?  I guess I could reach out to my new school's local chapter of this scholarship and fund a student, but what if I like one of my own student's research the most.  If I don't select the one I want to fund I fear it's wrong, and if I do select my own, then I'm using personal money to fund one of my "employees".  But giving to another university when my new place could use the money presents me with a dilemma.

Regardless, I will take part, if nothing else but volunteering with the organization.  I really enjoyed my experience with this scholarship, and I don't want to give up sponsoring students.  Should I?