Yeah, I agree with capn noe. Bitcoin "value" is far to unstable, I'm surprised that any businesses take bitcoins. Even during the past days before the crash, when valuation was reasonably steady, valuation fluctuated about 10% daily. And if one looks at the whole history its not practicable. Of course, in order for bitcoin to become more generally accepted, more people/businesses must use it, but as you don't want to hope for the best...
Sadly the only real thing I can think of is to drastically undervalue it in calculations. So right now I'd sell something I'd ask 50USD for @ about 8BTC, which seems a little unbalanced for BOTH participants.
An auction would let those buying kinda infer value, but even that doesn't work unless I have multiple buyers. If I'm selling, say, a catered dinner for 10 I seriously doubt I'll have 2 potential buyers ATM that would be going back and forth and establishing value as of the time of the bids (let alone if value changes dramatically after bidding happens).
Maybe someone is working on a fancy new kinda auction that compensates in some way?
