Josefl Assad offers a poignantly accurate analysis of current open-source sales efforts ("The Failure of Open Source Business Advocacy"). In short, we're selling the wrong value proposition. Open source sells itself on price quite often, but its long-range future depends on selling an entirely different value proposition: value and innovation.
The consistent and often exclusive focus on cost of acquisition as a competitive advantage is a key factor leading into unsustainable and sub-optimal deployment of open source. It is often the IT budget rather than the longer range IT strategy which provides an entry point for free software in the enterprise. The distinction is crucial: an annual budget at best provides room for tactical initiative, such as cost reduction or intermediate architectural adjustment. The core values defining how technology can serve the enterprise are rarely examined on a 12 month horizon, and it is arguable that the real business advantage to be gained from free software can only be realized through the adoption of the culture surrounding free software technology. For most enterprises, this is a long range proposition.
By advocating free software on the premise of immediate cost reduction, the implementing enterprise never acquires the insight that the adoption of free software introduces new and fundamentally different options for long range IT strategy. This has to be considered a failure since it trivializes the role of information technology in the enterprise: it is not the role of IT to be cheaper, it is its role to be better; and "better" however defined will normally drive at supporting the enterprise's core business more efficiently and more innovatively.
This is all true, and yet it doesn't resolve the near-term entry point for open source: price. Tactical though it may be, no open-source vendor is going to turn down a sale that is motivated by a prospect's appreciation for a low acquisition cost.
The trick, I suppose, is to upgrade the message to focus on the value that comes from shifting to an open-source mentality within IT while still allowing IT to function as it is and derive benefit from open source's lower acquisition cost. Customers aren't stupid. They recognize the price tag is lower. They don't need any coaching on that point.
So, open-source vendors can let the price speak for itself, all the while "upselling" the customer on the real, long-term benefits of open source: process innovation, improved flexibility, support value, etc.