CiviCRM is open-source. It's free to download and use.
The changes you make are all your own. It does not belong to a commercial company.
You can develop and configure it yourself. Or if you use Xpdient, then you have an initial cost, but no on-going costs, no matter how many contacts.
There is a vibrant development and support community, helping people just like you.
It's built by and for organisations like yours.