Well said again Scunner. Gets a bit scary to post sometimes!
I have 2 pure-bred Cocker Spaniels and, believe me, £300 isn't even enough to cover the vet bills for breeding dogs. The breeder where I bought them, who has since become a close friend, laughs about how she went into dog breeding thinking she'd make a bit of money and never really has. It's an expensive business. I believe OP was acting in the best interests of her bitch. Good for her.