db.x2gd.xlarge is an Amazon Neptune size with 4 vCPUs, 64 GiB memory (AWS Graviton2). In US East (N. Virginia) it costs $1.477 per hour on demand ($1,078.21 per month) for I/O-Optimized storage. It is sold in 3 regions.
Prices by region
USD per hour, I/O-Optimized storage. Reserved prices are no upfront, standard. Cheapest on-demand first.