@1
"Is 7 years old a good starting age" ++ To play chess: yes.
"to take a very expensive and serious course" ++ No. Do not waste money on an expensive course. Instead buy or download (for free: expired copyright) Chess Fundamentals by former World Champion Capablanca. In 60 pages it contains all he must know.
"learning to play chess and does win some"
++ Win some, lose some. The important is to learn from lost games.
Is 7 years old a good starting age to take a very expensive and serious course on how to play chess?
The school recently sent out a flyer on a course for beginners learning to play chess; needless to say he has been relentless and is currently learning to play chess and does win some.