Like others have said, saving a couple of bucks on a cooling fan is silly when you consider how much you paid for the rest of your components. Different brands do vary in quality greatly. In addition, many of the cheaper fans tend to be nosier too. I personally would trust a sleeve-bearing (Papst) or similar technology (Panaflo Hydrowave) over a no-name ball bearing.
Again I use the large OEMs as a benchmark for what I buy. In addition to Sunon, Delta, YS Tech and Panasonic, I also look at Sanyo Denki (used on Intel retail heatsinks), ADDA, Nidec (HP and Compaq), and a few others.
Windogg