Opening 151 Pokemon Center Elite Trainer Box (Exclusive) returns about $111.04 in card value against its $1264.45 price — roughly $0.09 back per dollar spent. On current prices, you lose money on average by opening it.
See every card and pull rate in Scarlet & Violet 151
How expected value is calculated — card value only, from published pull rates and daily market prices.
151 Pokemon Center Elite Trainer Box (Exclusive) on TCGplayer