cache.m4.large is an AWS ElastiCache size with 2 vCPUs, 6.42 GiB memory. In US East (N. Virginia) it costs $0.156 per hour on demand ($113.88 per month) for Redis. It is sold in 14 regions.
Prices by region
USD per hour, Redis. Reserved prices are no upfront, standard. Cheapest on-demand first.