Average price: 65.5kcr (including key)
Average estimated profit: 39.0640765kcr ~ 59.63981145%
Average estimated value: 104.5640765kcr

Content

Item
estimated chance to get from a lockbox looking at the prize pool of the prize boxes and their chances which are already known ~ average value of the item considering the standard color variations' chance to be 99%, divine/volcanic color variations to be 0.99% and the prismatic color variation to be 0.01%

Binoculars
18% ~ 11.5455kcr

Twilight Aura
0.5% ~ 4800kcr

Twinkle Aura
0.5% ~ 640kcr

Flower
18% ~ 85.616kcr

Prismatic Glow Eyes
4.5% ~ 525kcr

Headband
18% ~ 0.829925kcr

Long Feather
18% ~ 75.3295kcr

Plume
18% ~ 4.6275kcr

Wolver Tail
4.5% ~ 482.408kcr

All prices checked by the Lego Inc.'s price-check tool.

I spent a fair amount of time estimating and calculating the value of the Copper Lockbox, feedback needed. I'll keep updating the values as they change on the Lego Inc.'s price-check tool and I might do the same for other lockboxes in the future as well.