c3.large is an AWS EC2 instance with 2 vCPUs, 3.75 GiB memory (Intel Xeon E5-2680 v2 (Ivy Bridge)). In US East (N. Virginia) it costs $0.105 per hour on demand ($76.65 per month) for Linux; a 1-year reserved instance with no upfront costs $0.073 per hour, 30% less. Spot capacity is about $0.0261 per hour. It is sold in 11 regions.
Prices by region
USD per hour, Linux. Reserved prices are no upfront, standard. Cheapest on-demand first.