As I checked right now, Pro Plan will give you Orchestrator (cloud from UiPath), Studio licenses and also unattended bot.
It seems like the main difference is that Enterprise give you the on-premise option (so you could have Orchestrator and Robots on yours VMs). Of course you could negotiate the price when buying Enterprise.
You can check pricing here (for Pro Plan): UiPath Plans and Pricing | UiPath
According to that website I was able to choose one license for studio and unattended robot (my VM).