That's what a solid percentage of people do across the country. My brother in law is a huge NHL fan. His entire season ticket plan is north of $10,000 so he sells 2 out of every 3 or so above face value. It might not cover the entire package but it gets pretty close, and that gives him an option to get playoff tickets... same deal, except he makes a lot more off the top of the games he doesn't attend. The problem for most people is being able to pay the $XXXX upfront.
I enjoy catching a game on TV, so I think that's something I could do if I ever have enough money and live near a team I like. I'd catch the Falcons game every season plus maybe the Panthers and 2 or 3 random matchups that pique my interest (Dallas, San Fran, Miami).