Back in the 2019 Christmas Event you could pull this legendary gun from the Christmas Box. That box is long gone, so the only way to get Cavern now is through trading. If you like collecting Christmas 2019 items or just want an older legendary in your inventory, it's a cheap pickup. Don't expect it to move fast in trades.
Cavern (2019) is a Legendary gun in Murder Mystery 2. Its combined value is 1, #41 of 89 legendary items and #567 of 921 valued items overall. Demand is very low: it sits in inventories for a while, and buyers often ask for a discount.
Closest in value: Badger (1), Bats (2018) (1), Blossom (2016) (1). Use them as a benchmark for a fair one-for-one trade.
Value history
What it is worth in other items
1×Badger
1×Bats (2018)
1×Blossom (2016)
1×Blue Pumpkin (2019)
1×Bones (2016)
1×Bunny (2016)
1×Candy Swirl (2019)
1×Cane (2015)How many of each item equal one Cavern (2019) by value. Demand differs between items, so check it before you trade.