Blue Tooth OBD-2 scanners can be had for anywhere between $25 to $500 depending on features and goodies.
@Fixastuff said he paid thousands for his back in the day. As with anything else, the cost will initially be outrageous, but through competition and improved production methods (and payback on investment) the cost will come down. It works to our advantage that this technology is already widely available for automotive use so it is not starting from scratch. It is likely going to be a software patch to the ECU to unlock it rather than different hardware anyway. It will be interesting to see how it all shakes out.