I think the discussion whether or not designers charge too much is complex and to the ordinary user quite fathomless.
Fact is, price depends on demand, and obviously there is a great demand for custom skin designs nowadays. In general, you would not be a capable entrepreneur if you actually charge below what the market dictates (unless you want to kill the market through price dumping ).
That said, I'd like to share my experience with a designer who offered custom designs for only USD 99,00. After I had sent him my inquiry via web (I told him that I needed a new header, new footer, some new graphics, and I named him two forum designs for inspiration), he returned to me on the same day with a skin "preview" (as he called it). It was a screen dump only showing the top part (header and nav bits) of the skin. It didn't resemble any of the designs I mentioned to him. So I gave him a more extensive feedback, hoping, in return, to hear from him back. Instead, he fixed a few colors of his "preview", and changed one or two css tags. The result looked still as unfinished as before. Then we met on AIM to discuss the design (I suggested the meeting). Before it came to any real discussion, however, he disappeared from chat again. And then, only a couple of hours later, I received another email in which he told me to send the money to his paypal address. Slightly more annoyed at this stage (you can imagine), I pointed out my irration about his idiosyncratic customer practices. He apologized explaining to me that he had college work to do and was also very busy with up to 3 other skin requests a day. My response was short: I didn't want to do any more business with him. Well, now he still wants USD 60 for his "sleepless" night he spent on the preview.
As someone else mentioned before: you get what you pay for. This seems to be particularly true for the web design/forum design community. If you want to save yourself some headache, think twice (I didn't) before you go for the cheapest offer.
I created the thread not to discuss price politics. I was very well aware that "lite" skins cost about USD 200-400, whereas "heavy" skins cost about USD 400-800. I created this thread to discuss that we are actually lacking good vB designers! It turns out that there are still some promising talents among us, unfortunately, most of them still lack a more extensive portfolio. I hope this will change with the currently high demand of new skins.