Here are some tips in order to avoid being scammed.

1) If it is too good to be true, then most chances are that it is not true:
Avoid cheap offers, the cheaper price you can find these headphones is around $60 or so, anything below that price line is for sure a ripoff.

2) Sony puts a lot of effort in packaging and branding of their products, you wont receive a Sony product in a cheap box, never EVER. If the packaging looks poor, the user manual is just a little piece of paper and there are no Sony rebates / offers inside the box, then again, most probably you were scammed.

3) The real headphones come packaged with the following accesories:

• 3 Pairs of silicon earbuds in different sizes (Small, Medium and Large)
• A good quality leather bag to store the headphones when you are not using them
• A proper user manual and warranty card
• A good quality box and overall packaging

Now, an image is better than a thousand words, i took the time to create a really simple to understand image showing the main ways to identify counterfeit MDR-EX90′s, click on it to see it fullscreen.