The price comes down to where average people can afford it. However, it's still too new for most people to understand or use well. Recordable CDs are about here. This is the point where the general public begins to understand it enough to use it well. More to the point for skeptics, this is the point where it is in widespread enough distribution that unscrupulous individuals are using it.
People find it hard to imagine what life was like before it.
The telephone, TV, and cars have been here for years, in the industrialized nations, at least. The technology to produce good faked videos is maybe just barely at 4. The period between steps 5 and 6 will be a tough one for skeptics. I believe we will see a flood of faked photos almost good enough to be real, but the teeming masses will still not understand how easy it is to produce a fake, or they just won't care. The move to step 6 will have profound implications for society.