Aleen – firsthand I know of a similar maysoh. My rebbe’s brother, a mekubal in brooklyn, and a rov at the bnei yosef shul, told the doctors who were taking care of a comatose woman who had given birth before entering that state, that they needed to examine a certain artery, after he merely looked at her name on the mi sheberach list – sure enough, that artery was clogged, however the surgery was going to be very difficult because of the paitent’s health and other factors; i dont know if she got a refuah shelaima, but this is a more direct example – I too have heard this about the chazon ish, but it’s not too hard to believe..when you learn enough torah, you get a deeper perspective on things in both the ruchnius and gashmiusdige worlds.
I would not recommend buying it on ebay though..it could be a fraud, and there’s no reason to own it anyway, plus it would be impossible to verify if it was really his.