Correct me if wrong, but kivaloo isn't distributed. Jepsen seems fairly overkill without replication, partition, etc.

You are correct, as things are at the present time. I designed kivaloo to be composable with the intention that I could put a replication/sharding layer in front of it later, however.

I am genuinely intrigued about how much is costs to commission those tests. They are so complete and thorough that I can't see myself being able to afford one for some project of mine, but I would absolutely like to to have an estimate

Also, if you're willing to just write the tests yourself, Jepsen is open-source and Kyle Kingsbury offers a tutorial on how to use it on GitHub.

You might not get the same level of sophistication right away, of course, but that's just a matter of time and diligence.

Jepsen's website says you can contact Kyle at aphyr [at] jepsen [dot] io for pricing.