I'm really not sure about that. There is a recent "renovation" of a pumped storage site in Germany for more than 300EUR per kWh of storage capacity. Unfortunately I cannot find the original "Bürgerinformationen"-slides again. And it is a local, probably heavily politics-influenced provider, so maybe a lot of that is political landscaping. But I haven't been able to find a lot of anything with respect to storage prices beyond batteries. And I was really surprised that this renovation is the same order of magnitude than a battery installation.
You are still correct in the sense that storage is still incredibly expensive per hour of demand stored, but batteries may very well already be the cheapest option out there
This is our local Australian one, and the build price is an absolute joke which pretty much everyone puts down to incompetence, is 12bn. It's 5x the cost of the above linked battery for 120x the capacity (350GWh vs 2GWh). And this should be in operation for a lot longer than batteries.
German has no height. For their 11m pumped storage a battery may come close. But for the mountainous countries around hydro storage is much more effective and cheaper. They do have up to 1000m and more.
And they are terribly effective to hold the peaks and spikes. Austria and Switzerland are getting rich selling their peak capacity to the big countries nearby.
That particular reservoir may not have much elevation difference, but Germany is far from flat. There are many mountain ranges of a few hundred to over 1000 meters of elevation in the southern 65% or so of the country. They aren't impressive, but enough for pumped storage, at least if you only consider elevation differences.
Do you have some sources to their actual pricing? Some while ago I tried and came up blank. I assume your statements to be correct, because otherwise what would be the point of discussion, but I haven't been able to find any hard(ish) data
https://news.ycombinator.com/item?id=43624308
https://www.vox.com/climate/408381/energy-transition-renewab... | https://archive.today/sZFxF
https://www.eia.gov/todayinenergy/detail.php?id=64586
https://about.bnef.com/blog/lithium-ion-battery-pack-prices-...
https://ourworldindata.org/battery-price-decline