I don't think theres much of a market for errors and i suspect value depends on the type of error and/or what figure it is.
I got into for the chance of owning a one of a kind like this one.
Barbecue, with no silver paint on the lower part of the mask.
Cool thing is, this paint job matches the card art.
Have you ever seen a figure get a different paint job than it always gets and ends up matching the card art? Why has Barbecue always and forever been painted differently than the card art?
I also have 2 iron grenadier gold head Destros that have a black not gold studded neck collar to match the card art again
