Am I able to see an overview of how much I spend on contractor subscription fees?

Yes, you are. From the Company Settings > Contractor subscriptions tab, you're able to see:
 

• How many billable contractors you are being charged for on the Contractor Management plan.
• How many contractors you have on the Contractor Management Plus plan.
• When you will be charged.

To do any of the above: 

1. Go to the Company Settings > Contractor subscriptions :
   
   
   
    
2. Click on See more to get an overview of your upcoming payment and all the billable contractors you're being charged for.
   
   
   

If you're no longer working with a particular contractor, you can deactivate their profile.

Note: If a contractor on the Contractor Management Plus plan gets deactivated, we will treat it as termination of the Contractor Management Plus terms - their indemnity coverage will continue until the end of the month following the initiation of the downgrade and a 30-day minimum notice is required for this to take effect. For example, if a contractor is downgraded on June 15, they will be covered and billed for the Plus coverage until July 31.

See also: How to deactivate a contractor's profile