Irrelevant. People would simply breed the most profitable species exclusively, just as they do now.
All the more reason this shouldn't be implemented. Money is so easy to acquire, why create an even easier method?
At least with Payday, you have to be actively working to make that money...hatching eggs, on the other hand, is generally a passive process, once the flags are payed off.
Literally no work at all...and at the expense of shrinking the trade market.
Thumbs down.