What is the lifespan of a Macbook Notebook Hard Drive, and is it a good idea to replace them more then once?

Question

In specific, I own a 2007 Macbook Notebook, and it is an Intel Core 2 Duo MB21.00A5.B07. Last year, it became necessary to replace the hard drive, and was informed that the reason for the replacement was that the hard drive had reached the end of its lifespan.
My question is how long do Macbook notebook hard drives typically last? This also is in the context of frequent use of the notebook.
Additionally, is it a good idea to replace the hard drive more then once, or will the hard ware on the notebook, after I'm assuming about six or so years, be too out of date to accommodate a second or third hard drive replacement?
Also, since the replacement was still covered under an applecare plan (it's expired now), the general cost of replacing a Macbook notebook hard drive is not known? What is the cost generally expected of a hard drive replacement? This is in relation to repairs conducted at an applestore location (as opposed to a third party repair center). 

Answer 1

justinfromlos angeles wrote:
Also, this means that, the settings of a system like Snow Leopard, in addition to all other personal settings from a current hard drive, can be copied to and from an external hard drive?
Your entire system can be copied to an external HD in bootable form. It's generally referred to as cloning, and there are a number of applications available to assist in the task.
SuperDuper
CarbonCopyCloner
LaCie Silverkeeper
To name but three.
Furthermore, once cloned, should you have to replace the internal drive, it's easy to boot from the external and clone the system back to the internal.
justinfromlos angeles wrote:
If so, do you know where one can purchase an external hard drive and a replacement hard drive?
As I don't live in the US, it's difficult for me to reccommend retailers, but any computer store (including Apple) can supply external HDs. Be aware that not all HDs from some manufacturers will play well with Macs; Western Digital I believe needs careful selection of the correct model. There are plenty of contributors who can no doubt help on that front. Personally I use LaCie and Iomega. Note that these are purpose built externals and come with their own enclosure and all cables reqd.
One thing you will need to do with most of them is to use Disk Utility to partiton them correctly (GUID system for Intel Macs) and set the file system to Mac Extended (journaled) before cloning.
justinfromlos angeles wrote:
There is one last question. Say I've replaced the hard drive on the same computer for nine years or so. Despite the hard drive being new, would the hardware of the computer be too out of date to accept an up to date replacement hard drive?
The hardware of the computer dictates what sort of internal drive you buy; earlier models used IDE interfaces, current models use SATA and these are not interchangable. However System Profiler will tell you what sort you have. It's still possible to buy compatible HDs for the early iMacs, c. 1998/99 so there's no reason to believe your model will suddenly become defunct.