The following information was compiled by GSM Arena:
A Romanian online retailer has listed the MeeGo-running Nokia N9 for €550 on pre-order. If you want a more trustful source, Amazon.de takes pre-orders, too, but it's demanding €620.
This Romanian retailer is taking the N9 pre-orders for €550 (a hat tip to Robert S. for pointing it out). For a gray market price it sounds reasonably for the launch, although it's more expensive than most of the high-end droids today.
The German Amazon also has the N9 on pre-order, but it's even more expensive - €620.
So these prices should give us the basic idea of what to expect at Nokia N9's launch. It will cost a small fortune for sure, but we bet it will drop price in a month or so. After all the N9 is a smartphone with limited availability and doubtful support, so pricing should reflect that.
Update: We also received a tip from a trustful source that Nokia N9 will launch in Norway at €570 (incl. taxes) near the end of this month.