I've been slowly buying up Beta packs very cheap on Steem Engine and now also on Tron Watch Market I now have almost 2500 packs which i was able to get for anywhere from 30% - 50% off the retail price.
Sometimes I open a few when i'm feeling lucky (though I never seem to get anything good!) but mostly I'm just going to hodl until after they sell out.
2500 packs! Man, that's a lot! I opened 50 today. I got 1 Legendary summoner. I'm also not too lucky it seems. Therefore, I normally buy the cards straight up. It seems to work better for me.