I am awaiting a price on primed Hardi and painting on-site versus the pre-painted Hardi as we speak. When I get that answer, I will let you know.

I can't help you with Certainteed pricing though. That will be interesting to see what answers you get.

Overall, I think factory painted (either hardie or certainteed) will be less because of the labor involved with on-site painting.
Our "fiber cement" bid was all messed up...we did not get separate bids or competative bids, for that matter. Here's how our builder did it. They quoted a price for siding in our house bid which they listed as certainteed. I was a little disappointed because I had a hardi color in mind. From the bid, I assumed we'd have to use certainteed. Then, when it came time to actually pick the color, the siding contractor sent me samples from hardi, certainteed and a caulk brochure with dozens of colors. He said I could pick anything I wanted - the price in the bid would not change. It included the materials and his labor. This leads me to believe that hardi and certainteed are "about" the same price. The siding contractor is going to get his cut. Since he didn't care whether we used hardi or certainteed, I assume his cut was about the same for either product.
Hope this helps...

I got quotes of $145/square for Hardi and $123/square for Certainteed both pre-finished and uninstalled (i.e., material only). Pricing may be dependent on the part of the US you live in. We live in Maryland.

Thanks Sturdy. That info suggests Certainteed may actually be less expensive and I think it is a Texas company so may be even more affordable for those of us in state.

I got my price back for the Hardi painted versus unpainted(can't help with certainteed though)
For 35 squares of primed it is 9800.00 and add $4200.00 for the pre-painted.

That price isn't exact as it includes some of the primed shake style but I don't know how many squares of it, the shake was only $650.00 of that.

I am going to have mine painted on site as the painter has quoted $3400.00 to paint it so that saves a little.

Hope that helps!

The biggest part is the warranty. I think thats why they push the paint. Thats also why its cheaper to have your own painter do the job.

Here is a link that might be useful: Compare House Siding Prices Here.