A year ago, I got mine for less than $200USD. Seller was not a friend of mine and was purchased via DiMA forum. If I am correct, Ben (nurunet) gave me a hint where to look at and voilá!The only flaw it has is a missing/broken antenna, but leaving that aside, the model was purchased in perfect condition.
I wouldn't expend $300 or $400 dollars for a model that can be reproduced in future. The best example, is the IF200 KLM B744, people was paying over 300 dollars and a week later, PLOP, InFlight announced a new batch of them (different registration).
They key is to be patience and scavenge on every website or forum, spot the sale and get the model. Just this week a KLM Asia B744 was sold for only $160usd, within minutes the model was sold I guess. Damn, I wish I could be that fortunate buyer.
As Yoda would say: "Patience, my young padawan".