Stop eating, sell your car, sell your organs, etc.

Seriously though, it can be hard.  Aside from doing something that is "illegal"....... downloading the games for free from torrent sites..... there are very few options.

What I used to do in the past is have a bunch of friends who share the same hobby.  One of us would buy a game, someone else would buy a different game, then when we each got tired of playing that game we would swap.

Also my greatest factor for buying games is re-playability value.  I always search the reviews of games/game forums and look for words like "replayability", "sandbox", and "modding".  If the game has those three attributes, I get it (often times even if the reviews are negative) because I know I will probably save alot of money on not having to buy a new game in the future.  For example Civ 4, which was released in 2005, and I bought originally for $50 (I think) plus the Beyond the Sword Expansion for $30..... so total $80.  I played the Dune mod few days ago, and am starting to, 5 years later, finally get bored of the game.  So $80 = 5 years of entertainment.....

I did the free to play games, but eventually I just got tired of not being able to get the really cool stuff without forking over lots of money.

Steam sometimes has free weekends, where you can play a game for free on the weekend. 

I've gone through this thought process a few times, but I admit that I've not been very consistent in following through whenever I did make a decision. Often, just when I have decided to not buy any newly released games and wait until they hit the discount bin, an exciting title comes out that I just have to play. Even when I plan on buying only major titles in the genre, some never heard of game pops up that sounds so good that I simply must have it.

But sometimes I do succeed, and that's when I try out open source software and look for discount offers in my local store or at GamersGate. I'm no longer so much in love with the latest graphics, so that helps (I still bought a new video card for 250 Euro last year). There are plenty of gems to be had, and when a game has been out for a while, it usually has been patched and there are plenty of reviews. The downside is that the communities aren't always active anymore, which makes the whole experience a little less exciting. Being part of a new, evolving community is fun.

I've also had a phase where I bought mostly handheld games for the DS and the PSP, in an attempt to get more bug-free games and to get away from having to upgrade my computer every so often just to be able to play games without stuttering or other performance issues. This worked quite well for a while, but I started to miss more complex strategy games that aren't so common on handhelds, although they have a neat selection of turn-based strategy titles.

I've also gotten into Go, the Asian board game, figuring that it's a timeless strategy game, and that all I learn about it is "forever". I still play Go, and I believe it truly is the most fascinating strategy game, but it's abstract and like you I grew up with video games (got my first computer in the early 80s, and had an Atari 2600 before that), so the "need" for video gaming surfaces frequently. Go also didn't save me any money! I gathered a nice collection of books and imported semi-precious Go stones form China. Oh yeah, and a 12kg heavy Go board also. I could have bought quite a few games just for that! (Thankfully I resisted the temptation to buy Japanese shell and slate stones.)

I guess none of this is very helpful! The best approach is probably to just pick up older games when they are discounted. A year or two, and there are also games that age really well and that can be played for years. Dominions 3 is a good example, but also Age of Wonders 2 or the Civ series. Anything that's designed in an open way, allows modifications and supports randomization.

I agree with some of the others who have posted here.  Wait 1-2 to purchase your games.  You get better games (i.e. patched), cheaper price, and the hardware needed to run the game is less expensive.  Also, on the hardware side things have improved greatly.  I'm using a 4-5 yr old PC and have yet to find a game I can't play.  The trick is to buy a new "gaming" PC 6-12 months after the latest consoles are released.  This ensures your PC is slightly more powerful and most games have cross-platform development.

On the subject of "free to play", you are correct there is great value in these games but discipline is required.  They do a good job of extracting cash.  I'm up to $80 on LOL.  On the bright side, though, you are only paying for games you truly enjoy.