Oh dear lord.....your not getting it..... I used the same program back when i was a General Contractor bidding on jobs.....rebuilding homes, building new homes, building shopping centers etc etc..........How is rebuilding a home that has burnt to the ground not an "actual project" 
Of course theres competing going on ....... different geographical locations are different when it comes to materials and labor rates...the database for labor and materials in this program are all Zipcode specific...ie all regionally pulled from material suppliers and major constructon companies and construction management companies in a specific geographical location. If i wrote an estimate to build a home in lets say rural Pennsylvania.....and wrote the exact same estimate in say NY or Philadelphia...the bottom line on both would be completely different as the costs for both materials and labor are completely different, even tho line by line the estimates are identical...but my estimate better be in line with what the regional construction costs are or id never see a job ever........ Now If im building a new home, or remodeling/rebuilding a burnt out house the costs are completely different as construction methods for a new fresh build are different than a rebuild saving some of the original structure...even tho they may be in the same geographical location (which this program can also be set to price...ie remodel vs new construction.....
Your starting to make my head hurt
And you're starting mine to hurt also
. So you're saying that companies there do not make standing yearly agreements with the material vendors and go through an additional project specific RFQ process during the project bidding stage? Sounds like competition down there is really non-existant if you do not need to even know your bottom line while bidding.
Just out of curiocity, purchase prices of materials and services are considered a trade secret. Where does your software calculate those average prices from? Do your material vendors publicly publish their utmost secrets i.e. the cost price on which they provide their products to companies? That sounds pretty wild. If they publish their offering prices, how do the material providers then compete with eachothers? Again, they'd be publishing their trade secrets. At least down here material purchase agreements are binding agreements between two parties (constructor and the wholesaler or the manufacturer) and these agreements are never public. The public sales price of, say, a copper tube might be 2 USD/m but the contractor may purchase the pipe for .9 USD/m on small projects and .83 USD/m on a specific large project. The copper tube factory may give a specific price to a specific constructor on a specific project if they see it strategically fit.
Down here 500 000 dollar projects are won or lost on 1000 dollar margins. Nobody can afford to leave one rock unturned while pricing the projects. What you're saying about work costs is for granted, of course companies calculate the cost of work differently (regardless of the method they use for calculating) depending on if it's a new construction or if there's a slow renovation work which usually means also expenses of demolishing the old structures.
Down here the added cost for work price for renovation sites is about 16%.
Sorry this is off topic but it's very interesting to hear how this process works in your country. I'd like to continue the discussion on PM if you wish.
