the guy got real lucky and pulled a legendary card worth $7-8
I found this good vid on youtube which explains how to make some money playing Splinterlands..
You get these chests as rewards for winning battles. Opening chests u get either DEC (dark energy crystals), reward cards (worth a certain amount based on SPS value), and potions.
I think he said that u get airdropped SPS (the splinterlands in-game token) based on how much DEC u got. Then u can stake that SPS, which gets u airdropped even more SPS. :) sounds good to me!
So, the more battles u win, the more chests u get.. in those chests are cards, potions, or DEC.. and the more SPS u get, too. (which u can stake that sps)
the game really builds on itself.
the rewards seem trivial, but in the long run are NOT trivial.
So there it is, A basic tutorial on how to earn from playing splinterlands. Besides the fun of playing the game.. winning more and more battles, and acquiring more and more stuff.. there is definitely money to be made from playing the game.