I'm starting a t shirt design/printing company in a few months and looking at accepting Bitcoin as payment but I'm also struggling to work out how to tier it, do I have a fixed price ie 1 BTC or do I link it to the £10 GBP price I'll be charging and people will have to pay the fluctuating BTC price?
I think with e-Commerce, the benefit of taking a BTC is not the profit initially. I think if anything, you could and maybe should take a little hit price wise, to both give people incentive to get into Bitcoin and use it in a legitimate way, and then of course the word of mouth from that alone should overall be beneficially to your store in the long run.
I hope others can chime in with some thoughts on this, as proven by my sig I am going a different route

However I am more and more getting interested in other aspects. Like graphic design, I almost want to help the community a little by doing some start up websites logo or something simple, because I notice a lot of people have their heart in their work, but that doesn't mean poop to Joe A Websitevisitor. I am finding it hard to think of a proper pricing structure myself with that. I might go with 'for tips'
Back to your e-Commerce though, maybe do something the market hasn't seen before. Go by the average of whatever the set price of the top 5 markets is on Sunday midnight. Then for the week make that the "Bitcoin Price" of course if/when the price goes to whatever is opposite of what would be more positive for the customer, take that hit. It will act as a built in coupon. Just have a limit that the coupon can't be more than $5-10 or something. Seems wordy and hard to explain, but I would argue that the Bitcoin customer is a little smarter and maybe would appreciate such a deal.
Just tossing out ideas.