Well, if you really took good care of your disks they wouldn't get scratched enough to not play. One tip is to never leave the disc just laying somewhere out of its cover. Discs get scratched just from rubbing against a surface slightly, even if the surface is dirt free.
However, the so-called "disc fixers" usually just scratch the disc more. The way they work is by removing some the outer protective layer that has the scratches on it, but it's basically like taking really fine sandpaper, putting some sort of polish on it and scrubbing the disc outwards. The end result is not perfect from what I've seen, it just looks rough, but it may actually make badly scratched discs play, unless the scratches are really deep. Cheap disk fixers all basically do the same thing and the result is not great. There are professional ones that probably do a better job but they are generally not affordable by the average consumer.
You may want to look into any shops around you that might do disc repair as they probably have professional equipment for it.
However, this page has a lot of good tips that you could try that only uses common household objects you already have, and if that doesn't help you can always seek out a shop that does disc repairs afterwards:
http://www.wikihow.c...-a-Scratched-CD
It's probably not a good idea to try the waxing/light bulb steps as they may do more harm than good (and they're temporary so they aren't really a solution in your case). However the steps on that page probably work better than a cheap $25 disc repair machine and should have a good chance of working.
Just make sure to remember 2 things if you try any of the steps on that page: Never wipe on the side with the title, and NEVER wipe in a circle.