Oh, there's no way you'd be stuck with them--you can sell them at pet prices to good pet owners, making sure they understand that the animal should never be bred or placed with another animal. Just because they don't sell for $300 doesn't meant they wouldn't sell for $50, and that makes them no 'worse' than normals.

If someone discovered a morph that only reproduced itself 25% of the time, and 3/4 of the clutch were normals, no one would even BLINK--they'd love the thing. While there are considerations in terms of informing customers with this, I don't see it as significantly different.