I always think when people say "bucks" that mean they are in the states.
Anyway, even for beginners I'd say these Everlast aren't worth the price. If you look at the black piece of elastic band at the inner side of the wrist, that automatically scream rubbish to me. They will never have the decent wrist support especially after some use. Wrist support is pretty huge for a pair of boxing gloves, neither beginners or experts want to get injured in training, so...I will go on and tell you no on these pairs.
Yes, they are cheap but it's waste of money if they don't even worth that price. I'm sure there are better options out there and it might even be better if you consider increasing your budget for a good pair that can actually last him a long time.
Personally, it always works out this way for me: If you spend 30 bucks for a crappy pair that isn't gonna last or causing injuries/ unpleasant training experience to the point that you need another decent pair. You will end up spending the same price for the good pair with this 30 bucks on top of it. Plus seeing a pair of gloves lying around that you know you will never use is pretty annoying.
Also your brother is a big guy, pretty certain these kind of wrist support isn't gonna be enough for his power.