The altering prices is NOT a loophole. You can't even buy the items?
How do I know? Well a friend of mine posted on her blog exactly what it is and does. Good to know right? So now you don't end up going crazy over something that works! I know lots of people would probably give out rares for this, it's pointless.
Need proof? Click here.
She has used this price raising and knows about it. :)
It just lets you change the price that is all. Not buy or sell it, sorry.
So thank you PinkLady653 for posting this on your blog! :)