New Construction - Structured Wiring Questions

$75/run is actually quite common.  I'm not saying I like it, but it's a common price.  The crap you get for $80 is harder to work with - I pay closer to $125-$150/box for quality cable - the jacket is better and it's easier to work with.
On top of that, there's the jack, the patch panel or other termination - the mud ring, the wall plate... yeah it's probably $10-$15/parts per run - but labor - which has to account for the builder's profit, call-backs, and the costs of having a truck, the tools, test equipment, accusations that they broke your ______ and having to pay for it, etc...  Pros also [hopefully] use better quality name-brand components which, when all used together, create a complete system which includes a manufacturer's warranty and should actually pass certification with the right testers... 
Not defending the builders - just saying, it's not as crazy as it sounds when you think about it.
Personally here the decision relating to choosing a contractor to build a home (more than one in the last 15 years) related to permitting me or subcontracting LV cabling during construction.
If said contractor answered during the meet and greet "no" to my LV needs; then I went on to looking for another home builfing contractor.
That is me though.
You could also just walk away from the deal looking for a hungrier for business contractor.
In the end all that matters is monies made for construction of your new home by the contractor. 
Money versus no money made is better typically unless the contracted company doesn't care.
I agree that $75 per run is actually a reasonable number from the builder.  Not saying that I would pay it, but I think that is right in line (or cheaper) compared to other builders.  I said you would be shocked at the price...... ;)
$75 a drop is going rate.
While many feel it's a ripoff, if there is actually merit behind the installer, it's not a consequence of the cable, hardware and labor, but if there's actual testing and if they actually certify the cabling, then it's cheap. YMMV.
We've started certifying our CatX residential installs and provide a report. That gives us a leg to stand on when it comes to warranty issues or placing the issue when the customer states my I-port Linksys z-box isn't performing or my video doesn't work right or Netflix doesn't work right....well, unfortunately, we end up pulling out the reports and the certification file "as installed" then run a new test,  and you know how many of the mono-bay-depot-shack cables are the culprits? You'd be surprised. Sign the service ticket and have a good day.
I agree with Work's statement in post #16. Generally we use higher quality cable and components AND test our equipment after install (speaking for myself) in addition to the manufacturers we use on some jobs warranty the entire system: ends, plugs, cable, etc. if we use their entire product from end to end (example: ICC) and not the pot luck of Mono-bay or Ama-depot or whoever is chosen by the end user. It's not that the hardware or cable chosen from these places is inferior, but sometimes it really is!