Sorry if I wasn't clear. What I meant was:
Price the hire through a consolidator here (eg auto europe, holiday autos - there are loads) - it will be a pretty much all inclusive price.
Then price it (online) through a rental firm or firms in the US - these will probably show CDW as an 'optional' extra.
If you turn up and rent in the US CDW will also be an 'optional' extra.
For a short hire such as yours I'm not sure which will turn out cheaper.
You do need the CDW - if you don't take it you are liable for the full cost of replacing the car, and possibly lost rental fees, in the event of a serious accident.