I doubt Sharp's comeback plan is oriented around selling profitless $3000 TVs. Ergo, I believe they are making a decent profit even at $3000.
That said, it's probably not the same margins as Samsung's and LG's more profitable sets.
Aside: The Samsung "oops we of course meant we have 60 and 65 inch TVs" thing was very very weird. I am still skeptical we'll see much from them at 65, but certain we won't see anything from them at 70+ this year.
There is no difference in HDMI cables. If you can see the picture without visible dropouts or sparklies, the cable is working at 100%. No other cable will display a better version of that picture. You're simply wrong if you think there is a better digital cable than one that is already working.