The reason SBD is so highly valued is because there is incredibly little of it - only a few million in circulation right now. Even small purchases drive the price up significantly. A lot of the SBD was also trapped in Poloniex until recently, as they have had STEEM and SBD transfers disabled far more than any of us might like...

I am holding on to my SBD - at this rate we are going to be able to buy a nice car with a few hundred SBD in 2018. Wouldn't that be something? Even better, SBD goes to content creators (not curators), so it is nice to see rewards geared towards them do so well.