Hi Charlottesh,
I don't see any points to declare Private-sales.net is not legitimate - it was registered in California in 2009, they have a domain based email address and they have been at selling at eBay with 99.7% rating, with 63188 feedback count. They are also selling at Amazon. You may view their eBay feedback at Link hidden: Login to view
They are open to resellers and they require minimum purchase of $1000
for sellers to qualify for their wholesale pricing.
Hopefully we can hear from others who had the chance to purchase from them. :)