Opening 30th Celebration Pokemon Center Elite Trainer Box returns about $81.15 in card value against its $310.92 price — roughly $0.26 back per dollar spent. On current prices, you lose money on average by opening it.
See every card and pull rate in 30th Celebration
How expected value is calculated — card value only, from published pull rates and daily market prices.
30th Celebration Pokemon Center Elite Trainer Box on TCGplayer