Should I tip the Schwan's man & how much?

My order is 250.00 and he works off commission. I don't want to be stingy; however, I can't see giving him a 40.00 tip to carry in 15 small boxes of frozen food from the curb and setting them on my table. Am I wrong or is tipping him around 10.00-15.00 appropriate, are they allowed to accept tips? HELP Please! I want to do the right thing and have a good relationship with my Schwan's man.