The release of CS5.5 brings out interesting pricing offerings to Adobe customers. Instead of paying upfront the huge cost which cannot be managed by freelancers or college grads, they can just buy it for a month and continue as they use. Almost suites can be purchased via this new means including almost all individual applications.
You can find more details about the subscription offerings at www.adobe.com/products/creativesuite/cssubscription.html. The following video nicely summarizes the details of buying the subscription and managing it in just under 4 minutes: