But think of all the money you would have saved if you had played what you already own.
Not really, you only delay the inevitable
Not necessarily. If I had spent my time playing what I already owned instead of buying a new game, then by the time I finished the games I already owned, the "new" ones would no longer be new and would likely be greatly reduced in price. Maybe even available on a $5 or $10 Steam sale instead of $30 or $40.
Time is slowly teaching me that being an Early Adopter with paid software/hardware usually
means you get the short straw. In the case of PC games, a lot of them need serious bug patching for the first few weeks/months and are $50-$60. In the case of gaming consoles, usually in a year or two a newer model comes out with better features (though sometimes features are removed, as was the case with the PS3's backwards compatibility) and there's a price drop.
If I had purchased all my games for $30 or less instead of buying them new for $50 for the past 10 years, I'd have had hundreds of dollars to spend on other games or other things. And that's even if I had bought all the games I already own. It would have just cost less total because I'd have waited for the price to go down due to playing my games to the end.