I agree with quiltmaker...
I am working on my 4th memory quilt, and they've all been done for people I know. I don't know if I could work on one for someone I don't, because it is much more difficult/time consuming than making a regular quilt.
If it is someone you know, I would do it as a gift and sew in love and comfort to the family, kwim?
If it is for someone you kind of know, maybe charge a little bit for supplies.
This situation is much different than doing a memory quilt for a child going away to college, and taking all their sports tees and putting them together...