Well, it depends whether you need the banette EX or not.
If it is useless to you, then don't trade. If it is, then give it a shot.
Next, you need to know whether the Ho-oh EX will be useful to you.
If not then do the same as said above.
I'm just giving my opinions, I'm not forcing you to trade or anything. It's still up to you to trade or not.