Aye even so. They're definitely heavier to store, and their indexes can get quite big, though, so disk space / IOPS can be more of an issue. But still 2.3M is a drop in the ocean. (I don't know about HSTORE though…)

At my previous startup I was ingesting Hearthstone games at a rate of 1-2M / day. Before being handed off to permanent storage (s3, redshift etc) a bunch of data would get stored in a JSONB, with 14-day retention. This all ran on a 200GB t2.large instance on RDS, was our smallest instance and never really caused an issue.