I've worked on cars and motorcycles most of my life. I have bought numerous Hynes and Clymer manuals and the best I can say is that they are better than nothing. They really don't get into the detail that the manufacturer manuals get into. The Clymer or Hynes are probably ~$20-25 and the manufactures manuals are probably $50-125. If your just doing normal maintenance either of the aftermarket ones do ok, but if you get into more complicated things, it's better to get the factory manual. I bought a Clymer and a Haynes for my 1988 Iroc and ended up buying the Chevy manual. For what I was doing it was worth it.
I do agree that manufacturer manuals are overpriced, the Yamaha factory manual for my 07 1300 is ~$100, but I lucked out and got one on Ebay for $30.
I'd be carefull of some of the CD's manuals on Ebay, I bought one that said it was the factory manual but it turned out to be a scanned copy of a Clymer manual.