Those mufflers... they shouldn't be considered a selling point... or a factor in your decision. You can buy a pack of them independant of any set. 50-100 bucks.
And they're ok if you kinda know what your doing, but they really hinder playing. Your sticks get absorbed in them, the bounce isn't there, and forget about rolls. Not really something to learn on... just something to keep your chops up when you need to be quiet.
Plus.... lets be realistic.

Yer kid wants to play drums. He's not going to use these. He wont. So you prolly wanna forget about that and get used to the idea of real live drums in your house.

They're trying to sell that kit based on the mufflers and ease of travel. Two things you're not gonna need in a kit at this point.