currently has this set discounted 20% and it's been like that for awhile now. But maybe that was still too high. Maybe your threshold is 22% to buy and 20% to not buy. If that's the case, Walmart has a deal for you. They've beaten Amazon's price by another $10. It's sitting pretty at $309.99
with free shipping. If you live in a state where Amazon charges sales tax, you could be saving a few more bucks with the Walmart deal.
I wonder if seeing such consistent discounts on this set is indicative of it's popularity. This makes a great display piece despite the awkwardness associated with how to display the minifigs that comes with it.