While I might quibble with Christopher Dawson's choice of entry-level PCs the points he makes are right on.
Christopher alludes to lifecycle management but doesn't really explain why it is so important. The most important reason for lifecycle management is budgetary. Building into your IT budget enough money to replace an equal portion of your IT infrastructure each year of your lifecycle insures that as IT price-performance improves, your ability to keep up, and even improve the level of your IT infrastructure, can be dramatically enhanced.
Rule of Thumb #1: The ideal IT hardware lifecycle is three years.
While budget folks like to amortize expenditures over five years, this is not realistic for IT. And it places you behind when it comes time to upgrade those four- and five-year-old PCs. If you must live with a five-year hardware lifecycle, replace 20% of your workstations each year. Put your newest workstations in mission-critical roles and let your older hardware be hand-me-downs to administrators who need little more than e-mail and word processing. (And what better way to help administrators recognize the shortcomings of outdated hardware.)
Convincing non-technical administrators of the importance of annual budget line items for IT can be daunting. When budget consolidation (to pay for those big projects) is not an option, rolling over of small amounts from year-to-year for big ticket items in future years can be an important step toward uplifting the overall availability of mission-critical information technology.
Rule of Thumb #2: Don't assume the lowest retail price is the best deal.
For instance, it took me less than five minutes to find a $300 computer from Dell (after the rebate) with a faster processor and a monitor than the one Christopher found at his local retailer. Rather than shopping at your local retailer for bargain-basement computers for your school, seek out educational pricing from on-line vendors and their local resellers. Take advantage of school-system-wide vendor contracts whenever possible. Often, you can get more computer for the same money and without a doubt, you will get better support.
Consider buying the next model up. Blow-out prices almost always indicate a soon-to-be discontinued product. Rather than being stuck with a bunch of discontinued computers with no support in six months, buy fewer computers now for which replacements and spare parts will still be available next year. This helps maintain uniformity and reduces the number of different platforms you must support.
Rule of Thumb #3: Buy three years of on-site warranty with each workstation.
In the long run, this is a good investment and if a workstation has a motherboard failure in year 4, it is time to junk it anyway. (Other than the motherboard, most all components can be purchased off-the-shelf as needed.) If you have to settle for less, a one-year on-site warranty will at least get you past that critical period during which 'infant mortality' takes most computers.
Rule of Thumb #4: Buy your OS and personal productivity software (word processing, spreadsheet, etc) when you buy your computers.
OEM pricing is always lower and the need to upgrade this software during you machine lifecycle is limited. And don't forget to include virus protection. Specialized software is a different matter. New releases of these mission-critical applications are often upgraded annually. Buy these from your favorite educational reseller (online will often save you a few bucks) and if you can, purchase software maintenance and build these maintenance fees into your budget -- or face unexpected software upgrade expenses.
Rule of Thumb #5: Forget about that 'free' printer that they offer with your computer.
The inkjet printer they give you with each computer you buy will cost your school up to ten times as much per-page for ink as your alternatives. Instead, look for a modestly priced laser printer which can be networked to all of your computers. The per-page cost savings will be dramatic.
To be sure, in an educational setting facing shrinking budgets, these challenges may be daunting -- but they are not insurmountable and, after a couple of hardware lifecycles, the benefits will be apparent to all.