Was this too much money?

[flybye023]

We were on vacation last week and my sister had asked the 12 y/o son of a friend from church to feed our cat 2 times a day, clean the litterbox, put out the garbage can on trash day, water the potted plants outside and set sprinklers on the garden. She paid him $5 a day for the 8 days we were gone, so $40 total. (he's saving up to buy an iPod or something like that)

She stopped by today to pay him but he wasn't home so she gave it to his mom who said "no that's too much, just give him $10." My sister politely refused and left the full $40 telling her friend to give him however much she feels is right. Also, we're assuming the friend had to drive her son to our house twice a day so there's some gas money involved even though they're only a couple of streets over. My sister was a little taken aback about it though and we all started wondering what would have been a fair price. We (my mom, sister and I) still think $40 was fair.

What are your thoughts?