db.r6gd.16xlarge is an Amazon Neptune size with 64 vCPUs, 512 GiB memory (AWS Graviton2). In US East (N. Virginia) it costs $16.305 per hour on demand ($11,902.65 per month) for I/O-Optimized storage. It is sold in 8 regions; the cheapest is US West (N. California) at $13.328 per hour.
Prices by region
USD per hour, I/O-Optimized storage. Reserved prices are no upfront, standard. Cheapest on-demand first.