Oh dear. See what they say. I would think anyone selling a cockerel for that price is either selling really REALLY excellent stock or totally shady. If the connection is somewhat known, I would prefer to err on the side of Marans being notoriously hard to sex, so maybe if I was a younger chick when you got her it was an honest mistake? Benefit of the doubt???



In which case they should have *zero problem* making it right for you.
Or else you just got played. I really hope not though.
For a certain breed, I know a show quality breeder who would only charge $100 for a full grown, proven adult, significantly less though for a started bird. I want to say his started birds start at $70. Locally, various breeds of started pullets to laying hens might go for $20-30, generic quality, chicks would be less. Lots of times you find people giving cockerels away for free, and it just depends on the breed, if it's decent they might still charge $10-20-30. But I mean, either way $100 usd is kind of a lot to pay for a baby cockerel. :/