I've read that 10.6 frees up space when it is installed. I'm currently on 10.4, PowerPC. Will 10.5 free up hard drive space if I install it? Or will it use about the same amount as 10.4? Also, is 10.5 now on sale because its "old"? Thanks.
No, I think 10.5 uses a very similar amount of space as 10.4.
No, it's not on sale. It might go down to like $100 at some places instead of $129, but that might not happen for a while. Being the newest OS to run on PowerPC, most places will probably keep the $129 price.
You could look in the Marketplace forum here for a copy. You may be able to even find a sealed, brand new copy.
Leopard will take up about the same amount of space as Tiger. You could try running a program like xslimmer to free up extra space. Sometimes this does cause issues with program updates though.
I have not seen Leopard on sale anywhere. It will be before too long I reckon.