Has anyone used radiant barrier paint for a barn?

[Kyle_in_Tex]

I've been told the radiant barrier paint works well when sprayed inside directly on the metal with no insulation. However, this only works in hot climates down south. This does nothing for cold weather and if insulation is installed against the metal, it kills the paint's ability to work.
Has anyone tried this stuff?
The people I've talked to about building a barn for me are very expensive to install 3" rolled insulation.
Any feedback will be appreciated...Kyle