It costs $1M or so in the US to e.g. outfit an existing intersection with a set of traffic lights. I thought they'd be some gold plated, diamond encrusted traffic lights, but no, they're just standard issue. Constructions costs are pretty ridiculous.
If it's this simple why aren't other companies entering the market offering steep discounts? I don't see how such an arbitrary and vast margin could be sustained in the presence of even minimal competition.
In LA rail projects generally go to one contractor not because they are the cheapest (they aren’t), but because officials like that they worked on the previous project and have ‘experience.’ AKA nepotism and corruption.