https://en.wikipedia.org/wiki/Raketa
Look for ones with mechanical movements prior to 1990 or so (?); they were one of the last (or maybe the last) company making mechanical analog movements (non-quartz) long after every other watch manufacturer switched. Eventually, they had to switch too, but like 30 years later.
There's a story (pretty sure its true) of the czar buying a failing Ohio (?) watch maker, lock stock and barrel; literally, they bought the entire company and employees, and moved the employees to Russia to teach them how to make mechanical movement watches - and that continued on through the Soviet era.
But with glasnost, etc - that came to an end - and quartz took over.
I recently purchased one of these watches - it was fairly inexpensive (about $70.00 USD); it was a Lunokhod commemorative watch - with a 24 hour movement, and an orange face.
In many cases, you can get these watches as "New-Old Stock" - because non-quartz movements fell out of fashion, and the old stock just sat unsold. But now, with collectors learning about these watches, and the want for mechanical movements, they've come back. But because so many exist, they are still fairly inexpensive to find and own (even the really old versions of such watches).
There's far too much to write about these, but this article covers most of it:
https://www.hodinkee.com/articles/vostok-amphibia
For the in-depth engineering details, be sure to follow the watchuseek forum link. The interview with the designers is also good, albeit written in Russian so parts may get lost in translation.
For completeness I'll just mention the Poljot 3133, which is an excellent, low cost mechanical chronograph. It is the most technically advanced Russian movement, while the Amphibia is the most advanced case design. Poljot went out of business a few years ago, but there's still enough stock around that you can find plenty of new watches with this movement from companies like Volmax.
Vostok are still making new, fully in-house mechanical watches, and they are just as good or in some cases better than they were in the 90s. Meranom are their official online retailer. Note that Vostok Europe are a completely different company that no longer use any Russian parts, although they did use Vostok movements in their older models.
I personally would avoid older Russian watches unless you are prepared to spend a lot of time on research, or don't mind buying something that isn't what you were expecting. The vast majority on the open market are frankenwatches (mixed-up parts, often botched internal repairs).
If you want a new watch, I'd start looking at Seiko, Citizen, and Seagull watches in your price range.
Mostly because of the look. They have styles that are different, without being oversized, gaudy, or obvious knockoffs of expensive brands. The thin titanium ones are understated and nice looking to me.
If you decide on this path you'll need to do a bit of research and exploring first. A good starting point is this thread: http://forums.watchuseek.com/f72/buying-parnis-read-first-79...
If you value accuracy as in quartz, can't go wrong with g shock. Basically known for it's toughness.
Costs about $100 on Amazon.
1. https://www.wristwatchreview.com/2010/02/10/hamilton-pulsoma...
Generally though you would be fine with just sticking to the established brands. While I don't know what style of watch you prefer, for 300EU I don't think you can go wrong in terms of quality with a Seiko.
Many interesting models are sold only in Japan, but you can get them through SeiyaJapan or Higuchi-Inc.