I'm not sure if I'm missing something here but when I tried adding darts to my new character I was getting confused over the cost. The Dart equipment page lists it as 5 cp each which should be 0.05 gp. But on the character sheet when adding one it's shown as 0.01 gp.
That doesn't seem to be what the value shown is using to calculate total cost either because if I have 2 in my inventory it still shows as 0.01 gp - and only changes to 0.02 when I try adding 3 - it changes to 0.03 when I add 5 and so on.

Basically - it seems like DNDBeyond is erroneously using 0.005 gp as the cost for Darts which is only 0.5 cp and not the 5 cp it should be.
Am I mistaken? I'm really tired so I wouldn't be surprised if I am.

 I asked a similar question not long ago. Here was the answer I got:

Quote from Stormknight >>

Hiya,

there's a known issue where equipment costs in Copper Pieces are handled incorrectly.

It's a decimal place issue with the way those costs were entered and is on the active issue resolution stack for one of the dev teams.

 You are not mistaken, that is the case.

Ahh I see. Fair enough. I'll keep that in mind when I'm working out costs in the future.