Do you know the price break down of how utility projects are getting installed for $1.50/watt?
It can be less than $1.50/Watt outside of the US with PV available for less than $0.50/Watt. I know people installing complete residential grid-tied systems in the Philippines for $1/W.
First Solar modules are often used in utility scale projects in the US and since they build their own projects and First Solar modules are not sold to the public, it might be that First Solar modules are less than $0.40/Watt. Just to know the scale of First Solar, in 2014 the 2 largest solar projects in the world were 550MW each and installed in CA. 550MW alone was more than any state besides CA installed in a year. (Now Sunpower has the largest solar project in the world at 597MW, also in California.
Here is an article about how the module prices are coming down on the global market and expected to reach $0.36/W in 2017:
I think that prices in the US are artificially high for a few reasons. One being that we have a 30% tax credit on systems. People installing and owning systems would like that 30% to be as much as possible and some companies have been in trouble from the IRS for making the system cost more than it "should have been". Let me put it to you this way, if you were selling yourself a solar system and would get a 30% tax credit, wouldn't you sell it to yourself for $10/W if you could? With the Power Purchase Agreement, often the owner is the seller in a weird way. Reason 2 is the tariff that we have placed on Chinese modules after Solarworld and some others won a case against Chinese module manufacturers dumping (selling below cost) solar modules on the US market to get an increased market share.
To answer your question with some rounded off numbers for a utility scale system with a big disclaimer:
In many other countries:
Prices may vary depending on government, system type, sunshine, bureaucracy, interconnection, utility, and much more...
There are many utility scale systems outside the country that are selling for over $2/W because of equipment type, expensive land, paying off government officials, etc.