If I go onto Amazon right now, filter sellers by Amazon.com, sort by low to high, and look at the cheapest two TVs: Samsung UN24H4000 720p: $147.75 and LG 22LB4510 1080p: $159. Both "HD."
So, using HDTVs as a metric of poverty is dumb. They're the only game in town.
Which was the point.
Just pick anything that 90%+ of the population have: internet, electricity, gas, water, a car, heating, a telephone line, etc and then declare it your "line" for poverty.
If poor people could not afford televisions, they would likely be subsidized. The food stamp program provides the bread, and broadcast television provides the circuses.
How about tracking something that rich folk would be nervous about the poor people owning, like long arms or dissenter-friendly networks? How many poor people own an AR-15 and a software-defined radio?