that's a fine bike to start off on.
know that those suspension components are not toys tho. they need to be serviced every so often and it aint cheap unless you do it yourself. for example a shop will charge around 100 bucks to overhaul the fork. that's a significant portion of that bikes asking price. and it wont be the last time it needs to be done.
if he wants to start off on a very low maintenance bike, i'd keep looking. that yakuza will need brakes bled, and shocks dissasembled once inawhile or it will ride like crap.
it's still not a ton of maintenance, but sometimes it's better so start out on a simpler bike becasue there is alot to learn about taking care of them.
that bike is made for smashing picknick tables in half and general hooligan business. that's good if you plan to ride it really rough. but depending on what kind of riding you are doing it could be a little overkill. i wouldn't worry about that aspect of bike selection for a beginner tho. as long as the thing doesn't hurt you back or your ass then it's pretty much as good as any other.
im not sure if 400 is a great deal or not. sounds like it is...