Scaredycat….you are a funny guy in your own way! It is life to see issues in gray, rather than in black and white, and apparently you are rather skilled at this! Me thinks you thought you would start an interesting thread, and yes, you were successful!
If everything you do for your child is based on a monetary system, then I would have to agree with some of the other posters…it creates entitlement. Should money always be the reward? What about social relationships and connectivity and being good to other humans and life forms on this planet? What about the personal gains received from just doing the right thing?
I suppose it is best to look at the whole picture. You state your family has no TV, so paying for grades seems to go against that grain. You are obviously not materialistic, and recognize the problems coming from the media. Since your kid was not raised on TV (neither was I BTW, my father had us read “The Plug In Drug”) then your values would seem inconsistent to pay your son for grades. However, as mentioned above, it is all grays, so perhaps with the other values you possess, paying for grades is actually quite harmless. I guess it all depends on ALL of the factors combined.