This same Youtuber will regularly sell individual packs from a sealed booster box to be opened live on stream.
Here he is opening a 1st Edition Legacy of Darkness booster box, containing 36 packs that are sold to a variety of people. The last one sold on Ebay for $2150, so the packs were likely sold for somewhere around $60. I won't include shipping costs for PSA, assuming that the buyers would send in multiple cards together. How did each person do? Below are the notable cards from each pack, their raw prices, PSA 10 prices, and for added realism and to demonstrate the huge jump in price for the incredibly unlikely perfect grade, PSA 9 prices.
Person 1 - 1 pack $60 ($85 with grading)
-Dark Balter the Terrible - raw $10, PSA10 $150, PSA9 $40
Best case scenario made $65 (!!), likely lost $45
Person 2 - 5 packs $300 ($425 with grading)
-2x Bottomless Trap Hole - raw $5, PSA10 $70, PSA9 $43 (each)
-Second Coin Toss - raw $3, PSA10 $170, PSA9 $14
-Magic Reflector - raw $1, PSA10 $27, PSA9 $12
-The Warrior Returning Alive - raw $1, PSA10 $173, PSA9 $14
Best case scenario made $85 (!!), likely lost $299
Person 3 - 3 packs $180 ($255 with grading)
-Injection Fairy Lily - raw $75, PSA10 $1970, PSA9 $230
-Blast with Chain - raw $1, PSA10 $54, PSA9 $10
-Fiend Skull Dragon - raw $5, PSA10 $172, PSA9 $21
Best case scenario* made $1941, likely** made $6
IFL is this set's rarest card. Not only is a 10 very unlikely in general, but due to this card's extreme print defects even 9 is unlikely. It would be extremely lucky to get a 7, putting it at $80, a HUGE dip from the PSA10 and even PSA9 prices.
Actual best case scenario made $51, realistically lost $138
Person 4 - 2 packs $120 ($170 with grading)
-Twin Headed Behemoth - raw $5, PSA10 $96, PSA9 $20
-Royal Oppression - raw $10, PSA10 $150, PSA9 $50
Best case scenario made $76 (!!), likely lost $100
Person 5 - 1 pack $60 ($85 with grading)
-Susa Soldier - raw $1, PSA10 $133, PSA9 $23
Best case scenario made $48 (!!), likely lost $62
Person 6 - 3 packs $180 ($255 with grading)
-Blast with Chain - raw $1, PSA10 $54, PSA9 $10
-Freed the Matchless General - raw $5, PSA10 $350, PSA9 $70
-Second Coin Toss - raw $3, PSA10 $170, PSA9 $14
Best case scenario made $319 (!!!!), likely lost $161
Person 7 - 1 pack $60 ($85 with grading)
-Thunder Nyan Nyan - raw $2, PSA10 $125, PSA9 $11
Best case scenario made $40 (!!), likely lost $74
Person 8 - 2 packs $120 ($170 with grading)
-Reinforcement of the Army - raw $12, PSA10 $225, PSA9 $43
-After Genocide - raw $1, PSA10 $103, PSA9 $32
Best case scenario made $158 (!!!), likely lost $95
Person 9 - 5 packs $300 ($425 with grading)
-Array of Revealing Light - raw $1, PSA10 $92, PSA9 $9
-Luster Dragon - raw $5, PSA10 $270, PSA9 $51
-Dragon's Bead - raw $1, PSA10 $20, PSA9 $10
-The A Forces - raw $1, PSA10 $44, PSA9 $14
-Shadow Tamer - raw $1, PSA10 $120, PSA9 $35
Best case scenario made $121 (!!!), likely lost $306
Person 10 - 1 pack $60 ($85 with grading)
-Luster Dragon - raw $5, PSA10 $270, PSA9 $51
Best case scenario made $185 (!!!), likely lost $34
Person 11 - 4 packs $240 ($340 with grading)
-Susa Soldier - raw $1, PSA10 $133, PSA9 $23
-Exiled Force - raw $7, PSA10 $200, PSA9 $40
-Fusion Sword Murasame Blade - raw $1, PSA10 $100, PSA9 $10
-Lesser Fiend - raw $1, PSA10 $108, PSA9 $10
Best case scenario made $201 (!!!!), likely lost $257
Person 12 - 2 packs $120 ($170 with grading)
-Royal Oppression - raw $10, PSA10 $150, PSA9 $50
-The Warrior Returning Alive - raw $1, PSA10 $173, PSA9 $14
Best case scenario made $153 (!!!), likely lost $106
Person 13 - 1 pack $60 ($85 with grading)
-Yamata Dragon - raw $24, PSA10 $292, PSA9 $78
Best case scenario made $232 (!!!!), likely lost $7
Person 14 - 3 packs $180 ($255 with grading)
-Lesser Fiend - raw $1, PSA10 $108, PSA9 $10
-Dragon's Bead - raw $1, PSA10 $20, PSA9 $10
-Opticlops - raw $1, PSA10 $115, PSA9 $10
Best case scenario lost $12, likely lost $225
Person 15 - 2 packs $120 ($170 with grading)
-Fatal Abacus - raw $1, PSA10 $120, PSA9 $11
-Array of Revealing Light - raw $1, PSA10 $92, PSA9 $9
Best case scenario made $42 (!!), likely lost $150
Of the 15 people who participated, if we look at the realistic value of their cards, literally every single one of them lost money. On average, buyers lost $137. These people all threw away an average of $137 just to watch a Youtuber open their cards.
You may be wondering about the "best case scenarios" listed above. I cannot stress enough how difficult it is to grade a card at 10. PSA maintains public population reports for all cards. Let's take the chase card of this set for example. PSA has graded a total 1164 first edition Fairy Injection Lilys. How many were graded a 10?
64. That's 5% of submitted cards. People generally don't submit cards in poor condition, meaning 95% of cards that appeared near mint were not given a 10.
Odds are,
none of these cards will get a 10. Every single person involved in this lost money. And they didn't even get to open their own packs.
(Edited 37 seconds later.)