Marrow

I was approached by phone the other day by a national organization who matches anemia patients with possible bone marrow donors. I might match a two-year old kid with Aplastic Anemia. Apparently I submitted my blood sample back in '98, and now my numbers come up.
Why couldn't it be the Lotto instead? Just kidding... Sort of.
Anyway, I answered a bunch of questions about my medical history which I assume will conclude me to be clean. Now it's my turn. I gotta do some research about donating marrow. So far it seems, the risks are fairly low. Obviously it'd be a commitment on my part. Time, pain, risk of fluke death?.
The upside is I might save a kid. Upside for me personally is negative.

Here lies the moral dilemma.
Is it wrong for me to be selfish about this? Asking "What do I get out of this?" is clearly a selfish question. What if to save a stranger's life? Is it worth me losing a couple day's wages, risk at the very least some discomfort?

I have to admit. It was easy to WANT to help a stranger. But when I saw the picture of them drilling a hole into a donor's pelvic bone to extract bone marrow, it suddenly didn't seem so easy to say yes.

I'll move forward to see if I am in fact a match.

But at the risk of sounding cowardly.
I reserve the right to back out at any time.