Sedo is very, very, very bad at highlighting all the scammy domains where people have faked a normal-looking domain using a different (IDN) character set. There's just a brief note which is easily overlooked.
IDN domains definitely have their own place - we have over 2,000 in inventory, after all, most of which get traffic - but only if they're used the way they're meant to be i.e. all 1 language, with characters of that language (e.g. Chinese for a Chinese IDN, Japanese for a Japanese IDN etc.)
Where they go flaky is when scammers mock up an English-ish domain using character sets that have characters very "similar" to English ones, but just different enough to be utterly worthless.
