Originally Posted by
jsfr
One thing you might want to consider when you get to St. Michel/Notre Dame area is jumping in a cab and asking the driver to do a circle trip Notre Dame - Tour Eiffel - Trocadero - Etoile - Champs Elysées - Louvre - Notre Dame.
That way your Brother see a lot of the sights, on a Sunday in January it should only take 30 minutes and cost around €15...
Your suggestion is good, but it will cost more that E15. I would say more around 35.