I don't get this - if you know you want cabling done in the house, do your homework up front before you sign a contract with a builder. Know what you want and where and what possible future items you may need. This could take you a year in planning, but it has to be done otherwise you end up a creek without that paddle you so desperately need.
There is no reason that you should not be able to get access with your own subbie.
Hell, if the builder does not like it walk away - I did it for my house and I tell you what, I was very surprised at the company that I did go with. Project home builder are notorious for not letting subbies in, but the mob I went with let me organise my own electrician (my work mate which means me) which meant I had full control of the wiring (took me 6 weeks to pre-wire). Worked closely with the companies project manager on it and it was all pulled off in the end without a hitch. Communication is key in any project.
Now I don't lice in the US and so I cant fully understand what it is like there, but from what I can see, your economy is still up shit creek, so I would think that you as a consumer would have a LOT of pulling power.
Its you money, your house, not theirs - walk away and tell them to shove it up their arse and that they obviously have enough work to feed their family. It will be hard to do, but you will not be happy in the end unless you get what you want and not being happy is a bigger waste of money than being happy when its costs more.
Mick