From buying adult females, I have seen it good and bad last year.
One gave me 7 good eggs like the other years before the breeder told me. I am still waiting for them to hatch.
The other one was 07, a bit too small for breeding but since she took weight, I still breed her. Got multiple lock. Unfortinately she didn't go.
Meaning I am a year behind on my project. The good thing is that she is already close to 2000g and still looking slim (she is longer than large) and hopefully will gladly more than make it next year.
In the end, I put a lot of money in these girls and even if they don't make it right now, they will pay for it later. Should I have bought younger ones instead ? or more younger ones ? May be, may be not. It's up to you to do the calculation and the risk involved.
Most of the time it's not worth it. But risk is part of the game and part of the fun I think.
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love this world, don't hate it.