Is he offering to compensate you in some way? A nice dinner? Pizza and beer? Because if not, no. And it's not selfish to not want to be permanent tech support or to decide not to help someone with a really involved task for free.
Is he offering to compensate you in some way? A nice dinner? Pizza and beer? Because if not, no. And it's not selfish to not want to be permanent tech support or to decide not to help someone with a really involved task for free.