Product review (5 stars): OEM Samsung Dryer Belt
It's cheaper than direct from Samsung. Also, it's much cheaper than local parts stores that ask for double to triple MSRP and they don't have it in stock. I bought 2 to save a future hassle. It is identical to the original that broke.

Replacing the belt yourself is a bit of trouble, but there is a video on youtube.

Sidenote: Do not buy an extended warranty through Samsung. I am still annoyed that they lied to me about the duration of my warranty. Luckily, this was not too difficult to replace yourself.