Well unfortunately, no amount of complaining and whinging on a forum is going to change what your friend is doing.
What will you do if said friend comes across this thread - just google a few words and it'll come right up on the first page of google.
Have you actually confronted this friend? And questioned (nicely) why she is breeding her mare to this not so great stallion? Maybe suggest other stallion choices?
As for prices, well, a horse is only worth as much as a person is willing to pay. She might be putting 10k on horses that we don't think are worth that much, but hey, there might be someone out there that falls in love with the temperament, is cashed up, and is willing to pay that much money. My yearling's asking price was AU$14 000 as soon as he hit the ground, he was purpose bred as a dressage horse. Now I was happy to pay what I did for him, as to me, he is worth that. But to someone who wants a western pleasure horse, or a racing horse, he's worth jack squat.