cache.m4.xlarge is an AWS ElastiCache size with 4 vCPUs, 14.28 GiB memory. In US East (N. Virginia) it costs $0.311 per hour on demand ($227.03 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.