In my own game, it appears that the price for the 100% guarantee has only risen to 5 Farm Cash, but some farmers are reporting that they'd been charged 10 Farm Cash (that is, if they were willing to pay it) just for a single Lamb and pattern guarantee. While this could just be another attempt at Zynga to "test the waters," and eventually settle on a number that users will pay, if they weren't having success earning money at 3 Farm Cash per Lamb (if they were, why are they trying again to set a right price?), what makes them think 10 Farm Cash would be any better?
This is one time that I'm truly confused farmers. Hopefully, the price will land closer to 1 Farm Cash where it belongs, but for now, I'd suggest sticking away from the option entirely so you don't end up paying anything more than you "have" to.
What's the price for 100% pattern inheritance in your game currently? What's the most you would ever pay to receive a Lamb with a guaranteed pattern? Let us know in the comments.