Tororider,
Your numbers are correct. ICF does cost more but you have a bomb shelter in the end! A standard poured bacement is about $7.50 a sq-ft of wall. Your construction costs may vary, but around here 10' tall poured 8" thick wall is $75 a running foot. Alot depends on; step footers, window/door openings and number of corners. A plain rectangular bacement with out windows is fast and easy. Mine had step footers, doors and windows on 3 sides due to 'walk out' basement feature. The abvantage of ICFs are; 1) DIY friendly. You get a solid poured wall with out renting forms. The pouring contractors had the market cornered due to investment of their forms. They stack like Legos and cut with standard wood saws. The blocks have internal webbing to place and hold the Rebar. I am using Fox blocks. They sell without dealers and reps and they list there prices on the web. My 8" concrete core blocks cost under $3.00 a sq-ft. The other advantage,2) is drywall ready/siding ready. The blocks have built in nailers/studs every 8". The ele is placed in grooves cut into the foam, 2 5/8" thick. The outside is ready for any standard siding as well as stuco. I will use stuco due to the design. Windows can be 'trimed out with foam. just paint/texture a different color. This stuco method is very close to EFIS. You see alot of comercial building finished this way, foam and stuco. Several sites offer the material, fiber mesh, adhessive backing and the final topping for about $1.50 sq-ft. 3) very energy efficient. The standard fox block has 5 1/4" of total foam. At R-4.5 per inch, that's R-23.62. I will glue an additinal 2" of foam to the outside so my end result will be R-32.62. You really can't compare framed wall R-values with ICF R-values. Stud walls have 'thermal breaks' every 16"/24" corners and windows even worse. The R-19 stated for 2x6 framed walls insulation is based on the pink area only. I have seen reports where 'whole wall' R-values can be as low as R-12
There are some good web sites for ICF, do a search but be sure to check out Fox blocks.
Patrick T.