Propulsion
The buck stops here.
I can't easily quote monthly figures because I have many instances doing many different things in my AWS account.
What I can say is that last month, the most that I was charged for a T2.medium with 6 masternodes was $1.58 per day. My monthly bandwidth fee was $7 (but that includes all manner of instances including several C3.large)
Take things one step further. Here is what the EC2 price calculator says for one fully utilised T2.medium with 5 EIP (you can run six masternodes with 5 EIP if you launch new instance), 10GB intra region traffic, 1 30GB SSD and 100GB internet traffic.
So roughly $55 a month instead of $130?