If I've understood correctly the CL packs purchased from Hive Engine don't contribute towards getting promo cards, only packs bought from the Splinterlands store. I can't figure why anyone would by them for $9 when you can purchase them later for $3.6 when public sale starts.
By the time of writing this, my understanding was there were only 2mio packs left for 'normal' public sale (and that maybe a big chunk of them would be sold under the table) - so I expected them to be sold out very quickly.
Now I've been told it will be 12 mio. packs in total.