Q: Do you charge for bandwidth?
A: Yes. Plans start with 1TB per month and increase incrementally. Once the monthly transfer limit has been exceeded it is $0.02 per GB thereafter.

Can I limit bandwidth to ensure not being charged?
For example, if the bandwidth reach the limit, instead of being charged, my droplet would be turned off.
Is there any way to do this?

We do not currently support this but if enough people request this we can look into it.

We track feature requests at:
http://digitalocean.uservoice.com

You can use vnstat and monitor it. Once it reaches 999 GB u can automatically turn off your droplet

I might write some code for this in near feature, so stay tuned.

Ok, wrote it here we go.
You need 2 things installed:
1. vnstat
2. bc

#!/bin/bash
ax=`vnstat --oneline | awk -F ";" '{print $11}'`
if [[ "$ax" == *GiB* ]];
then
if [ $(echo "$(echo "$ax" | sed 's/ GiB//g') > 999"|bc) -eq 1 ]
then
shutdown -h now
fi
fi

This shuts the droplet down, once it exceeds 999 GiB of traffic.

And here to keep the spacing:
http://pastebin.com/2vXMBaSi

I suggest to let it running every minute via cron.

I will sign in the coming days and test the script. Thanks fs!!

thank you fs! Just what I was searching for