There are many open source solutions that are supported by an organisation, and that helps a lot when considering trainings and consultants.
But when the point is contracts, for a database or an ESB for example, some companies don't consider open source solutions, as there is no legal responsibilities for impacts on the adoption of the respective solution.
How can we present open source solutions to larger organizations, and how would we deal with these responsibilities?
This is a tough issue that has prevented lots of large companies to move to a more open source business model.
Most companies don't understand that just because your code is free doesn't mean you won't make as much money. Options:
If you are a sales representative or just a large supporter of open source material. Some things you could do are:
explain the benefits of using open source. These are things such as better code, more usable interfaces, customized software and hardware and less bugs and issues.
Explain to the company that open source does not mean less money. Often when people think of open source they think that the code is free so, therefore, no money. This is not the case.
Explain the helpful community that they could be apart of.
Conclusion
This will not work for all people or companies. Despite your efforts to convince them it still may not work. Some people may be scared of the idea or even confused. The best way is to try your best.
Educating people about stuff they don't know about can often lead them to like the idea.
Cost effectiveness and use of resources. Let's use your example of a DB system.
You still need hardware to run it all on. That's a "fixed" cost. Using F/OSS won't really change it. You still need a sysadmin/db admin to install/configure/maintain it - that is a "fixed" cost. A fastastic *nix+Postgres guy might cost a little more than a fantastic Windows+MSSQL guy, but not that much different. You still need developers to write code for your product(s) that use your DB system. "Fixed" cost again.
You can pay Microsoft for a license for SQL server, Windows Server to run it on, etc.
Or you can use Linux or BSD with Postgres, Mongo, MySQL, etc. at no license fee/cost. No per user, per cpu, per server, etc. If the CxOs say "but what about support" there are quite a few businesses out there that will do short term (implementation/migration) or per-incident support contracts.
Then the intangibles - no forced upgrades, no worries about product discontinuation, freedom to easily move out of that system and into another, etc
