Alexander Mcqueen (possibly McQ?) Skull Sailor Dress

Found it at a thrift store Missing two rhinestones It says small, fits like a 6 and has a ton of stretch Apparently this designer’s a big deal in the UK Can anyone help me price this I genuinely don’t know what its worth I can't find any dresses like it online so I'll accept respectable offers If this sells for $500+ the poshmark guys’ll appraise it for me thankfully