I'm not nearly invested in this enough to confirm my estimates here but I'm sure someone more diligent will gladly correct me cuz ain't that what the internet is all about?
Whether you have Sunday NFL Ticket or not, you get approximately the following games for free (depending on how free you consider the prime time games on Thur/Sun/Mon):
TNF: 17 (1 per week except for week 18) + 2 extra Thanksgiving games (3 total that day)
SNF: 17
MNF: 17
CBS/Fox 12pm/3pm Sunday games: 36 (At least a combined total of 2 per week or 3 whenever one of them is airing a doubleheader)
So that's 89 "free" games right there. With the expansion to 17 games, they now play 272 games per year. That leaves 183 games up for grabs minus any sunday afternoon local doubleheader games.
For just one team, you'd expect 3-5 prime time games. Split the difference and call it 4 so you'd be getting 13 extra games instead of 183ish. 13 is about 7% of 183 so a proportional price for one team would be like $21.
If anyone wants to clean up my numbers or breakdown, have at it.