1.6 odds on this is excellent in my opinion. Bitcoin has actually been ranging roughly between $5,000 to $10,000 for the better part of a year now, there isn't any major reason why it should shoot up or down in sight.
Even though the odds have currently dropped slightly, I would still say it's a decent bet. Logically the odds will start going down naturally since we're getting closer to the expiration date.
Seriously tempted to put a huge stack on this bet, as I really cannot see it losing. I'll open up a highly leveraged long and short at the same time just to hedge my bet.
definitely agree 1.6 is value for the 5k - 10k range. Nice to see betfair offering markets for this as it will help giving BTC exposure among punters.