However in the UK if we put 141 before the number we want to call it makes our call untraceable. Im not sure what it is in the US but you must have some kind of similar thing?
You can surely block your number from coming up when you call them, but that will be an immediate red flag. Pay the money and link a phone to your account that you can both receive and make calls to them. In my opinion it is one of the most important things to staying stealth. $10-$20 per month is cheap insurance to keep up and running.