"It may sound crazy, but it might make sense to abandon vendor support if an organization has highly modified the software, is running on an older release no longer supported, intends never to upgrade, or plans to migrate from the system in the near future," Scavo added. "Vendors have increased their fees for software maintenance to the point where they may not be justified in a large percentage of cases."

[Read about another seemingly radical 21st-century IT idea: "IT heresy revisited: Let users manage their own PCs." ]

"Going naked," as Scavo calls it, works in very specific scenarios. "When we know we are moving off the platform at the useful end of life of the software, it might make sense not to renew the contract," Yale's Mayes says. But for the most part, the risk is higher than the cost, akin to driving around without auto insurance.

"The question is, how critical is it? If the system is down and you can't get it started, can you go back to the vendor? Or can you get someone else there right away?" Duncan Jones, a senior analyst with Forrester Research, probes. "If the knowledge base of known bugs and patches is out there, it can work. If not..."

Matt Aslett, enterprise software analyst at the 451 Group, describes the risk bluntly: "It would take a brave company to run an ERP [or CRM] application without official support given the criticality and complexity of ERP apps."

Alternative approaches

Few companies would consider enduring that kind of risk with a mission-critical application. Instead, they would be more likely to consider two popular options to lower enterprise software costs: SaaS (software as a service) or open source. Instead of slogging it on the upgrade treadmill, jump off and try something new.

With SaaS, support costs are similar, but maintenance costs plummet, since the vendor hosts the application. With open source, the business model generally relies on for-pay support, but with a robust enough community, adroit customers may be able to get away with minimal support and rely on the assistance of peers. So far, however, few large companies have made the leap to SaaS or open source enterprise applications.

When subscribing to SaaS applications from the likes of NetSuite, Salesforce.com, SalesNet, or Workday -- or even Oracle or Microsoft SaaS apps -- the host handles upgrades. Be aware, however, that per-seat subscription prices track pretty closely with the conventional licensing, maintenance, and support costs of on-premise software. You get quicker time to market and avoid up-front licensing costs, but factor it all out, and you may not save much, particularly if you add subscription fees to extra-cost options.