Effort : This is the additional work to be done in terms of person-hours. If we opt to deploy in containers on top of Kubernetes in order to reduce cloud provider lock-in, this item would include the effort to learn a new tool, write Docker files, configure Kubernetes, etc.
Expense : This is the additional cash expense, e.g. for product licenses,
Version lock-in : Besides being locked into a product, you may even be locked into a specific version. Version upgrades can be costly if they break existing customizations and extensions you have built (SAP, anyone?). Other version upgrades essentially require you to rewrite your application - AngularJS vs. Angular 2 comes to mind. To make matters