DTV tuners (and I expect ATSC 3.0 tuners) are much smaller and cheaper now. You can get a DTV tuner with rudimentary DVR functionality for around $30. For ATSC 3.0, there will likely be some considerable technology licensing fees (HDCP, h.265, Dolby audio) that weren't there 11 years ago.
At intro, or 5-10 years out?
No doubt, ATSC 3.0 tuners will be inexpensive WHEN AND IF the transition is successful. The transition will only be successful if there is a well thought out transition plan, if TV manufacturers can incorporate ATSC 1.0 and 3.0 tuners at a reasonable cost, and when broadcasters see a reasonable percentage of sets with 3.0 capability to justify cutting off the 1.0 feed. No broadcaster will have the bandwidth to provide both and also provide the popular subchannels.
The current plan is to simply throw it over the wall and see if something develops. Frankly, we tech geeks are not going to be the ones to make this successful. We need Joe 6-pack clamoring for improved football, and if he feels that the current 1080i on a 50" set is good enough, it isn't going to happen.