Hi all,
  I'm in the planning stage for building a home in S.E. Arizona.   Climate there is moderate, snow is rare in the winter and high summer temperatures would be around 105 degrees.
  The home would be about 2000 sq feet livable, and I have to keep the budget as low as possible. 

Has anyone who used both SIP and ICF that can give me a general pricing comparison? Any recommended manufacturers in the area? 
Thoughts?
thanks,
kris

In AZ it can be tough to compare total performance/$ since the high-mass of ICF can improve both comfort and performance at a given steady-state R over SIP technologies. (The thermal mass effect is often overstated when applied to heating-dominated climates, but at higher & drier cooling dominated climates it's a real factor.)

For 1-story slab-on-grade buildings ICF can be quite reasonable, even as a DIY. It gets more complicated for 2-story or with full basements, etc, when the height of the ICF is18-20 feet or There's no simple comparison that can be made between SIP/ICF without more details, but when all else is equal (when did THAT ever happen? :-) ) ICF may have an edge on several fronts.

I got bids for ICF and SIP for my 3 story (basement +2) construction. SIP panels including installation labor were 1/4 to 1/2 the cost of ICF. I am in the process of building now. If everything goes to plan the SIPs will end up 1/4 the cost of ICF.

seriously doubt that SIPS will be as low as 25% of ICF.

however, SIPS is a good choice - just that ICF wins out on several other inherent advantages.
please let us know cost per sq. ft. here someday.

(www.ecologicalarch.com)

i am making the assumption that you are also using SIPS roof in any case.