Will updating ios 7 on my iphone costs charges on my bill using cellular data?

I wanted to update ios 7 on my iphone 4s using the cellular data, will it costs some extra charges on my bill afterwards? But i do have hotspotshield VPN elite, does it helpful?

Don't use your cellular data. You'll end up using up to 1GB for the download and if you go over your monthly limit you'll get charged an arm and a leg extra.
Find a Wi-Fi hotspot somewhere.

Don't do system updates using a data plan. No those would not help. If you want to update it on your phone, use a Wi-Fi connection.

You can't. That is to say when you run an update or upgrade to the IOS it will ONLY work off of Wi-Fi or using a hotspot from ANOTHER phone or device. The phone can't update the IOS from cellular data. And in that case yes since a hotspot works off of cellular data and the file is nearly 2GB is size.