They can easily tell the first 1,000-2,000 people who sign up that they are of the first 500 people who HAVE to pay 100% as soon as they get an email from them. Where's the accountability that there would ONLY be 500 people offered this option.
You're correct, but possibly misinformed. You can
choose to order from the second batch now, the idea being you don't have to cough up (in full anyway) until the first batch (0-500) units are confirmed as legitimate.
http://kncminer.com/categories/minersThat being said, you are correct in stating that we have no way of knowing if the "first 500" item is truly limited to 500 purchases.