Re: Foundation Costs
if you have actually contacted a few foundation companies about this and their numbers are all coming in within 5% of one another that number should be correct for you area. one thing to realize is that not only are these contractors going to be supplying the materials within that cost they also have tradesmen installing it who have to be paid along with overhead along with any state taxes on top of that. the semi typical equations for the cost is figure out the material cost and then double it, this of course doesnt always work.
its great that you'd like to do it yourself, however... ICF's are a engineered product which has strict guidelines on how to install it, mostly to do with proper rebar scedules and bracing up the forums for when the concrete is placed so that you dont have blow outs and everything stays plumb. because of this in most regions all icf foundations HAVE to be built by licensed installers as they have not only taken a 2 or 3 day course on the product but have also built atleast 3 foundations under the supervision of a carpenter employed by the company that produces that specific brand of block. i state this because i am licensed on both NUDURA and ARXX, in my region there is only a small number of companies who are licensed on this product and even fewer general contactors who have turn-key carpenters who are capable of installing a icf foundation and then each and every other step of construction.
im not trying to discourage you, just stating your local building authority may not let you build with icf unless you hire someone to aid you along the way to ensure everything is done to the drawing.. its one thing to cut one board short and need another.. but to pour a foundation that ends up wrong and then have to jackhammer it out and redo it is going to cost you well over $20,000
fire up the saw and make some dust