I own a computer hardware shop and I was thinking about it many times to add a bitcoin as a payment method. The only thing that is stopping me till now is how to convince our accountant that things won't be that hard to calculate. She is a bit negative about it as she don't understand the concept behind the bitcoin / as many others/ We've been working for almost 10 years now so I don't really what to change her but.. we have to find some solution.
If you do it through BitPay, or other payment processor, and get it auto converted to fiat (100%), then, from accountants perspective, it makes no difference whatsoever.
Accepting BTC directly creates some extra work for her, which you'll have to pay for, so makes little sense if purchases in BTC are rare and insignificant.