Yep, as ozgunner has highlighted, easy to get caught on a seriously under valued load, and then you risk getting the load tied up in red tape for what can be weeks.
They pretty much know the value of popular products, so can pick an undervalued load without too many issues. Of course they can hold the load up even if it's a genuine declaration if they even get sus, so having good accurate paper work will always smooth out any lumps in the road.
Of course most companies need to maintain accurate book work for their own tax records, so most won't be interested in undervaluing, however it does happen.
If it's your first time importing I would suggest just going with someone like DHL. They'll take care of everything for you, and even though they won't act until a package has been held up by customs for more than 48 business hours, if there is a problem beyond that they are able to assist in sorting through the issue for you.
Bottom line, not worth the risk from any stand point really.