Free
According to Apple's own Web site you can buy the Mac OS X 10.6 (Snow Leopard) for $22.99.
Currently, it's $129 dollars (Mac OS X Leopard). Once Snow Leopard is available (August 28), it will be a $30 dollar upgrade from Mac OS X Leopard.
This depends on the use-case scenario. OS X 10.6.x has support for legacy (PowerPC) applications, whereas that functionality was omitted from later releases (1.7.x and 10.8.x). So if you need applications written for older versions of OS X, you don't have much choice. But if not, definitely go with the later versions.
$19.95
Apple's Mac OS X. OS X Lion OS X Panther OS X Leopard etc.
The second name of Mac OS X v10.4.5 is Mac OS X v10.4 Intel.Mac OS X 10.4 was known as Mac OS X Tiger.
As of August 2014, it is not possible for a person to upgrade OS 9 to OSX. A person will only be able to upgrade to OS 9. 2.
There are two Firm Suggestions currently; OS X Saber tooth or OS X Cougar
Mac OS X 10.4 (Tiger) needs to be purchased as it is not possible to update from Mac OS X 10.2.8
Mac OS X is an operating system released by Apple Inc. It is designed for Apple branded computers, which is why you will never see a Dell, or an HP computer run Mac OS X. There are only two important versions of Mac OS X, Mac OS X Server, and regular Mac OS X. Mac OS X server was designed for servers, while regular Mac OS X was designed for most computers. The current version of Mac OS X (10.6) is named Snow Leopard.
Macintosh OS X Tiger is an OS (Operating System) made by Apple. Mac OS X Tiger has nothing to do with tigers. The purpose of an OS is to run programmes on a computer.
No, it's not. But Vista has similat to OS X interface, at this point it was derived from OS X.