In my experience, the visual design actually takes longer than the HTML/CSS (I can slice a PSD and make clean, compliant code for an entire site in like 8 hours). It's sort of a whole process, and definitely more valuable than the equivalent of $65 worth of Bitcoins. I'd be very surprised if it was 5 BTC total and not per hour.

If you think about it, you need an index page, level 1 page, and possibly other types of pages depending on what CMS your site uses, if any. Colors need to match, a navigation scheme needs to be chosen, link hover properties, etc. The whole user experience and functionality needs to be factored in when developing the design. It's a lot of work

The other question is, what kind of support does OP provide? Can I call up and discuss my needs on the phone prior to development of the template? Is there a feedback/revision process included in that price? And so on.