Fully agreed.

Thanos puts data to object storage. The most popular options — GCS and S3 — have the following monthly costs now:

• GCS — from $4/TB for coldline storage to $36/TB for standard storage. Additionally the following resources are billed: egress network at $10/TB for internal traffic and $80-$230/TB for external traffic; storage API calls (read,write) at $0.4-$10 per million calls. See the pricing for details.
• S3 — from $4/TB for glacier storage to $23/TB for standard storage. Additionally the following resources are billed: egress network at $2-$10/TB for internal traffic and $50-$90/TB for external traffic; storage API calls — $0.4-$100 per million calls. See the pricing for details.

The summary storage cost depends not only on the data size, but also on the amount of egress traffic and the number of API calls.

VictoriaMetrics puts data to block storage. The most popular cloud options — GCE disks and EBS — have the following monthly costs now:

• GCE disks — from $40/TB for regional HDD to $240/TB for multi-regional SSD. See the pricing for details.
• EBS — from $45/TB for HDD to $125/TB for SSD. See the pricing for details.

VictoriaMetrics is optimized for HDD, so there is no need in over-paying for SSD. VictoriaMetrics provides up to 10x better on-disk compression for real-world data comparing to Thanos based on Prometheus tsdb — see this article for details. This means that it requires less disk space comparing to Thanos. This usually results in lower costs for storing the same amount of data comparing to Thanos.