I'd say that if this outfit is willing to offer the configuration that you outlined at a pre-defined price - $599 shipped - to anyone who contacted them, it may be appropriate for this forum. In such a case, they should just advertise it as such on their web-site.
But if it is based on haggling with them then it is no more appropriate than the deal that I got with another ebayer who sold me a monitor at what I considered to be a good price after a number of email exchanges. There was no assurance that he would sell the same monitor to anyone else at that price.
I just checked their website and all that they appear to have are the ebay auctions.