db.r6i.4xlarge is an Amazon Neptune size with 16 vCPUs, 128 GiB memory (Intel Xeon Family). In US East (N. Virginia) it costs $2.784 per hour on demand ($2,032.32 per month) for Standard storage. It is sold in 29 regions.
Prices by region
USD per hour, Standard storage. Reserved prices are no upfront, standard. Cheapest on-demand first.