There are several salary study firms (some old school like Radford, some new like levels) and the answer you can buy from them depends on the question you ask.
If you want an answer to “what’s the median base salary for SWEs in the US?”, they can sell you the answer. If you want to know “what’s the P75 SWE salary?” or “what’s the P90 SWE salary?” or “what’s the P75 SWE total comp in the cohort of these 12 top employers of SWEs?” those are all also available, but numerically quite different from each other.
You could call any of them a “market reference point” with a straight face.
I don’t know how it scales for different size companies, because firms like Radford do some significant inquiry and processing on your data as well (as inputs to the system) and I wasn’t involved in buying that data.
Levels has a data feed service they sell that’s an initial dump of N months of history and then a daily dump of additional ones. That was modestly priced (I think that was low 5 figures per year, but in any case it was quite inexpensive relative to running a software operation).
As an individual or small employer, I think levels is an amazingly valuable service (for free). When you get larger, buying these products makes more sense. (We’re remote-first and even still spend more on soda and coffee in a year than on salary data; I’m sure the salary data does more to attract, motivate, and retain than the soft drinks do.)
If you want an answer to “what’s the median base salary for SWEs in the US?”, they can sell you the answer. If you want to know “what’s the P75 SWE salary?” or “what’s the P90 SWE salary?” or “what’s the P75 SWE total comp in the cohort of these 12 top employers of SWEs?” those are all also available, but numerically quite different from each other.
You could call any of them a “market reference point” with a straight face.