yes. these are the equivilent of the untraceable cell phones in new york. they are a 1 time use for a job so they will go up pretty quickly. it would be worth your time to stock up on at least 100 of them maybe more. i am only on tier 4 and already i have used up over 30 of them. there may take more in tiers 5 and 6 so i am stocking up currently as well.
The key is to not finish off the boss. That way you can continue to go back a level to get the Sattelite phones as needed. If you finish him you have to complete a few more jobs to reach the spot where you can grab more phones. I'm on 5a and I've already been through 100's of these phones.