I don't expect their home phone number, but at that price point an email address that I could expect an answer from in a couple of days is certainly called for.
I bought NGUI because Unity's UI system is complicated. If I wanted to spend all day learning how to use a UI system, I don't need to pay Tasharen for that. I could do that learning the Unity UI system for free. If NGUI isn't substantially easier to use, it's not of much value to me (certainly not what they're charging for it).
mail support is not practical, since nobody else can read the given answers, a forum is really much better way to get support, not only the authors can give you answers but other people using the product can too, and you can search the forums for similar issues. If you look at it that way, you'll see how much better it is than mail or a mailing lists for support.
you don't have to spend a whole day learning it, just watch the first two tutorials (less than 20 mins all together) and you would be ready to get started, and if you're feeling wild you can spend 20 mins more on the 3rd tutorial, it's even all indexed so you can skip the parts you don't want to know about.
trust me, those vids was the only thing you needed to get started, and they are so clear and well explained.