This goes back to what each person feels like he or she needs to pay. If paying on NET is what you feel you need to pay then pay away. If he feels the need to pay on Gross then let him pay without questioning why he pays that way.

For me, it comes down to what I was brought up to pay. You pay on gain, you gained a certain amount, yes the government took some, but I don't feel that is any different than hey I put 10% into 401K before taxes, so lets pay less that too.

Why turn it to do you feel the need to pay more to get into heaven? That is really uncalled for if you ask me. He is paying on what he knows and feels is right. If you want to ask him why, I am all for that, but to ask if he thinks paying more than everyone else is not right. There were more than 1 person that said they also pay on Net so seems maybe it might be more than you think.