Most of the time he immediately replaces himself with an equipment (and you even have the choice of which one from the top seven)
Like most Magic: The Gathering cards, the value of Murder depends on a few consistent factors: its rarity, the printing and finish (regular or foil), its physical condition, and the set it was printed in (Murders at Karlov Manor)
As such, the decks contain a few goes-in-basically-every-deck staples, plus a few stapes-in-the-making
Foraco Scale (500g x 0.01g) With a microscale, it is possible to determine the exact weight of a Magic card
Or just think about how much better Monastery Swiftspear is than Soul-Scar Mage
If Locker Room is worth a third of a card I could see Bottomless Pool being worth it, but I suspect Locker Room will be worth less than that