My sentiments exactly- IMHO they look like crap, and you might as well mount the curb feelers and neon while you're at it. Those tires aren't going to even make D code, and a PSD 'X' weighs 8200#.
Sell 'em, and put the money into what the 'X' really needs- E rated tires, U or V code springs up front, Timbrens, Rancho 9000's, and a rear sway bar.
The 'X' is a great truck- I have put a lot of miles on my PSD 'X', and it's a damn good tow vehicle as well, especially when you make up for the deficiencies that were there from the factory.

Don't put anything bigger than 20" on the Excursion, I have a 1/2 ton Yukon XL with 22" Antera's (silver, not Ghetto chrome for those who assume your from the hood if you have big wheels)
Anyways I went with the Nitto that is a 45 series, I would prefer to have the Pirellis but I did not want the 40series tire, I pull a 29 Scarab, sometimes to the river as well and no problems.

The ride is a little rougher, but the look can't be beat, not to mention for a big truck, the thing handles like it's on rails

I work for a company that supplies wheels for SUV's, even up 24" and in my opinion 20" is the best when it comes to functionality.

As far as the price, call Globe Tire in LA, CA. (310) 836-0804, and see what the wheels sell for from the market that they come from, and then you will know how sweet the deal is

Jimbo