question on 12 year old boy's spending habit

My son's best friend is a 12 -year-old white boy. My son and his friend are in the same basketball club, play guitar together, and always go to the same summer camp together.

Overall this is nice boy, smart, friendly, active in school , his school work is above average.

His mom and dad only have one kid. Their financial condition is just above average, not very rich, but they got power boat , 4 plasma TV, spend a lot on travel. and they allow their son to have a lot expensive brand name cloth, video game, etc, they gave their son $50/week allowance. The boy used all his allowance for movies, clothing, food court. I think this boy and his family enjoy big spending.

This family like my son, his mom told me that my son could have good influence on his son( school work, reading habit, out of school activities..), so they always invite my son for boating and go to fancy restaurant.

I think this family is not bad, but I don't like their spending style, I brought some brand name cloth for my son to match his friend, that's fine, I think it is good for growing boy. I agree some resonable cost on travel and leisure. But I don't like their spending habit, it may be bad influence on my son.

I don't know how to deal with this, my son will be unhappy if I don't allow him to get along with his friend, or even say negative words on his friend.

Do you have suggestion?
thanks!