Measured data point: I ran a read node on Hetzner (cax31, 8 ARM vCPU, 16 GB RAM, 1 TB volume) at $0.164/h, so about $120/month if you keep it. The DB was about 560 GB, so 1 TB is enough today, not 2. A full test run, sync to teardown, cost me about $3.30.