Video games are really a rather inexpensive hobby. Let's not count the PC cost for a minute here.
Fallout 4 at the stated $100 - 400 hours of play (assuming you do not use mods) - $0.25/hour. That's not bad.
Going to a movie First Run movie - $9.00 - 2 hours - $4.50/hour. (Not counting popcorn, soda, etc).
Median cost for a round of golf - $36.00 - 3.5 hours - $10.29/hr.
Going for a nice drive in the country - 30 miles round trip - 1 gallon of gas $3.14/gallon - 2 hours (with stops to relax) - $1.57/hr
So really, it is one of the most inexpensive hobbies around. And if you add in the startup costs - a computer is expensive, sure. Going to a movie isn't that much, so that's a decent choice (but all the time?). Golf clubs - that's expensive. A car sure isn't cheap, unless you buy an old one, but then, that comes with its own problems.
Are there cheaper hobbies than computer gaming? Sure! Is gaming expensive? I guess it depends on what you are using to measure it against and just what you get out of it. If you only play a game for a few hours and then chuck it, ya, it's expensive. If you play the heck out of the games - I'm still playing Fallout 3 and New Vegas, no clue how many hundreds of hours I've put into them - then...not so much.