You can get the original PC release from JAST USA DRM-free from their store if you'd like. The current publisher/localizer of the series will likely not change their minds on DRM-free stores like GOG.com, so this is an option if you'd like:

https://jastusa.com/steinsgate

Well, thanks for bringing this to my attention :)
Perhaps I missed it before, or perhaps it got changed some time ago. I don't know.
PCGW only links to this http://steins-gate.us/ which DOES currently have link to what you linked BUT I am not 100% sure if it wasn't previously linking to physical release instead (I think so, I kind of remember seeing that [am I from paralel worldline? :S], but I'm not 100% sure).
Unfortunatelly webarchive isn't helpful, last capture is from 2017:
https://web.archive.org/web/2017*/https://www.pcgamingwiki.com/wiki/Steins;Gate
https://web.archive.org/web/20170328203030/https://www.pcgamingwiki.com/wiki/Steins;Gate

On a side note:
The collection of hentai's below in the "other users buy" carousel is slightly disturbing :P Not that I care. I don't play these kinds of games. It's just kind of silly it's there like that in completely unrelated game's page.

A link to "physical edition" leads to 404 https://www.jlist.com/p/sg001 .
What;s interesting is that it seems to be still available just the link is wrong:
https://www.jlist.com/sg001
I guess it wouldn't hurt to notify JAST website admins (I will do that maybe in a week [IF I manage to contact them] since I'm really busy with different things now).

Afaik there are differences between JAST and MAGES versions:
https://steamcommunity.com/app/412830/discussions/0/350541595108955587/

I could theoretically get the Steam version someday and "make it" DRM-free through my own efforts (I don't know the engine nor how deep any theoretical DRM in it may be atm) (which I did intend on doing).
But seeing that there is indeed DRM-free release, and on top of that DIRECTLY FROM PUBLISHER WEBSITE, well, I'm in a pickle.
I would kind of wish to get the MAGES plus community patch. But then I care for TRUE DRM-free (I don't neccesarily mind MAKIND Steam version such and just moving files around). So I'm shredded between choices.

Have you played it?
Which version would you advice?

(I could of course get MAGES on sale plus the other, it's just that I am short on money and so I have to "choose wisely" "for now")

I actually own the original Limited Edition release for PC that JAST USA released which uses the same translation as the DRM-free version on their site. The crew that did this original translation were the same crew that worked on the fan translation, and are credited by their names/handles in the final credits in the JAST USA version of the game (but are not credited in any subsequent releases). Since the JAST USA version is based on the original JP PC release, the overall resolution/fidelity is lower than the Steam re-release, but I found the actual fonts and text integration were stylistically much better in the original PC release.

The Steam release - while with worse font, weird translation changes, & some weird text overrun in places - did get better (and become the arguably definitive version) through mainly fan patches (http://sonome.dareno.me/projects/).

Ultimately - you might be better off getting the Steam release since the mods by the dedicated fan community have brought the overall quality back in line with the original JAST USA release. Especially if you're playing the game on any kind of HD screen bigger than 15", you'll probably prefer the HD presentation of the Steam release.

tl;dr - it's really a toss up - I played through parts of the JAST USA PC releasefirst, and I still prefer it's translation overall, but given the warm reception to the Committee of Zero modified version of the Steam release - that might be the better way to experience it now. I just wish the original translator team would've been properly credited in future releases, but I guess it just wasn't to be.