Ink jet cartridges are often rather expensive, and don't take very long to wear out if used frequently. Two ways to get a discount on cartridges is to buy them in larger quantities (even buying a package of two or three instead of one will usually bring about substantial savings) or purchase a cartridge which is generic or re-manufactured. As an example, here are some of the different per-cartridge costs you could pay for a HP 45 or equivalent black ink jet cartridge:

Location, Type	Quantity	Total Price	Per Cartridge
Radio Shack, HP	One	$31.99	$31.99
OfficeMax, Generic	One	$25.49	$25.49
OfficeMax, Generic	Two	$45.49	$22.75
OfficeMax, HP	One	$29.99	$29.99
OfficeMax, HP	Two	$52.99	$26.50
Staples, HP	One	$29.99	$29.99
Staples, HP	Two	$52.99	$26.50
eBay, Generic	One	$7.98	$7.98
eBay, Re-manuf.	One	$4.48	$4.48

When deciding which type or quantity of inkjet cartridges to purchase, the customer must take into consideration how long the printer will last, how much printing he or she does, and whether or not it is worth the risk that a lower-quality discount cartridge will not function properly. It should be kept in mind that cartridges which have been stored too long may expire.