Thank you for all the kind words and comments and for linking to my piece. I don't want to get into the minutiae here, except to say the following:
My price range of $350-$550 is based more upon gut feel, not technical analysis. If I use the technicals, then it is most likely the psychological barrier of $400 - $436, but I accept that markets overshoot technicals intraday. I think the equilibrium point is somewhere in that range.
As a corollary to my "gut", I'm seeing a number of high net worth individuals and funds who are long Bitcoin looking to reduce their average holding price from the $800-$1000 range and are continuing to pour dry powder into the market. I don't know how long this will last, but it's a stabilising factor to some degree. Given the high beta upside of Bitcoin, I don't think we're going to see a bottom much lower than $350, given that Silicon Valley is awash with liquidity right now and the general consensus is that Bitcoin has high upside. The real question is how much selling pressure comes from Coinbase & BitPay.
Again, the title of my piece was aptly named - "Finding Equilibrium", no-one knows for certain what the true value of a Bitcoin is but it's really a factor of balancing fiat into Bitcoin and fiat out of Bitcoin that will determine the short term price. The long term utility and use cases of Bitcoin are yet to be defined and proven and as a result placing the value on a single coin is undeterminable right now - it's just speculation and psychology intertwined.
External factors aside. If Bitcoin lives up to half the promises and expectations from it's enthusiasts, the outcome will be a price greater than 10x the current price. So, if you assume a 10x payback, you would buy Bitcoin at $450 if you thought it only had a 10% chance of success. On the basis of that logic alone, I'm still a buyer... (and also a keen poker player, of course)