When you could just buy 2 Random Champion Shards insetad. So far I've bought 12+ Random Champion Shards this event, and literally ALL of them were at least 4800 BE champions, which can be disenchanted for 960 BE, and quite some of them were 6300 BE champions, which you can disenchant for 1260 BE. And Random Champion Shards only cost 50 tokens.
So instead of getting 1000 BE for 100 tokens, you can get 1920, 2220, or 2520 BE for the same price, and it's pretty consistent if I didn't get a single shard of a champion that's less than 4800 BE buying 12 Random Champion Shards.
Why is 1000 BE even included in the event shop?
Edit: someone confirmed in the comments that you can only get 4800 and 6300 BE champion shards from the Random Champion Shards, so you're guaranteed to get at least 1920 BE for 100 tokens if you buy random champion shards.