When it comes to paying for content, i'd much prefer to pay a decent amount for an expansion, than small amounts for DLCs.
Cheap DLCs are very annoying. Not because of the cost, but all the hassle that surrounds it. Take android apps for example, my google account already has my credit card on it. It takes literally one button, the thing is bought, it gets downloaded onto my phone. And if I ever change phones or have to reset it, it just downloads again automagically.
With cheap DLCs, often that involves yet another website that needs my credit card details. Also, if it's something that you have to pay for, often there's authentication / drm involved (although I guess with the witcher this could be an exception). Either way, it means more hassle if I need to install the game onto a new computer, or if I need to reinstall it.
Often the hassle of paid for DLCs is about as bad as the hassle of dealing with a drm game. >.