Deal has not expired yet. If you click on "other sellers" or "new from $19" you can still have these for $24, but not two day shipping and not through prime. These are just OK from the reviews though. Better choices out there...they look cool though.
^ I wouldn't put much stock in reviews of headphones. "Good" sound is too subjective. I've seen $5 junk get good ratings but then once something costs over $15 people start comparing against cans costing much more for some odd reason.
Comments & Reviews (2)
The same is true on headphone oriented websites but those tend to go into greater detail, including what some sound like after a break-in period.
http://www.head-fi.org/t/615580/akg-k512-mk2-any-thoughts-on-sound
Thank you!