I think he's using GCP with a new account, so he received a $300 free credit.

But I couldn't find machines with 8vcpus and 64gb, only 8vcpus with 32gb

90-day, $300 Free Trial: New Google Cloud and Google Maps Platform users can take advantage of a 90-day trial period that includes $300 in free Cloud Billing credits to explore and evaluate Google Cloud and Google Maps Platform products and services. You can use these credits toward one or a combination of products.

https://cloud.google.com/free/docs/gcp-free-tier#free-tier-u...