Not sure if anyone has noticed this yet - but it appears they have changed the item weights this event.
Let me explain. Previously most items would start between 1-3 gems to buy them individually and go up in cost proportionally (similar to buying cells). Basically this meant each item had an equal weight yielding a more smooth progression. This event it seems one item is given a very high weight. You can tell which one it is by looking at it's initial cost along the bottom.
For example, Lepu's "Fight" items have a very high weight, meaning doing the simple fights drop the buyout cost (progress) very quickly every 2 hours.
Fightreer's, however, major item is the Breed item (initial value of like 30 gems!). This is bad because the price will stay very high to complete unless you do all of the breeds (he needs 11 at an 8 hour cooldown a piece).. This will likely make his node (and others like him) take a lot longer/more expensive to complete.
I think this is going to make this event VERY hard/expensive to complete. Even with the double items I fear this may be borderline unfair.
I'm already on Fightreer with only spending around 30 gems, however he poses a significant roadblock. I'm not confident this one will be like previous events.