Union Arena That Time I Got Reincarnated as a Slime vs SAKAMOTO DAYS booster box: which is worth opening?
SAKAMOTO DAYS is the better box to open: its cards are worth 127% of its price after selling costs, against 54% for That Time I Got Reincarnated as a Slime.
Side by side
| That Time I Got Reincarnated as a Slime booster box | SAKAMOTO DAYS booster box | |
|---|---|---|
| Verdict | Keep it sealed | Toss-up |
| Box price today | $162€145 | $94€84 |
| Cards inside, after selling costs | $88€78 | $119€106 |
| Cards ÷ price | 54% | 127% |
| Boxes that lose money | 83 of 100 boxes | 71 of 100 boxes |
| A typical box (median) | $46€41 | $50€45 |
| Rarest pull | Alt-art parallel (★ / ★★): 66 of 100 boxes | Alt-art parallel (★ / ★★): 66 of 100 boxes |
| Packs | 16 packs of 12 cards | 16 packs of 12 cards |
| Released | June 26, 2026 | May 29, 2026 |
The two boxes
How we work this out
Both boxes are worked out the same way: today's card prices, selling costs taken off, and simulated boxes to see how often one loses money. Read the full method