I want to buy a printer ?

You should buy a used Kyocera printer like Kyocera FS-1030D, around 30-50 Euros. Toner is also cheap, and it's not a big device, even has builtin duplex printing unit and 22 pages per minute.
I had a good working Canon/HP laserprinter in the past. But currently all it gives is paper/jam.
What was funny, the price of the printer was the same as two times the price of the toner.
I think one toner was good for 2000 pages.
Mono Brother laser. HP charges too much for cartridges and makes it very difficult to use non-HP ones. Brother cartridges are reasonably prices for the mono, I think, but am not sure, that you can easily use generic toner, and the ppd files they offer for Linux used to, at least, work with FreeBSD. I've not used one since I got my color laser years ago, but if I were to buy another printer, it'd be Brother.
Another thing to consider is, if the toner and the drum are in
one cartdridge, as in HP printers, or separated. The toner may be much
cheaper, but one must consider the price of the drum, normally

I have only experience with old HP printers. I have a LJ4L and a LJ 2420.

How is it with the here recommended Brother, Kyocera FS-1030D
and Samsung?

And another thing to consider, is, how much dust it generates, but
to get information about it may be not very easy.

For me, Laser is very important, because I use the printer
for documents to be kept a longer time, I do not trust ink.

Postscript or PCL 5e are important for easy configuration.
How is it with the here recommended Brother, Kyocera FS-1030D
and Samsung?
Well Kyocera has separation between toner and drum. The average lifetime of such a drum is 100.000 copies, so in order to reach that you really have to print a lot.

And then a new drum unit comes around 100-120US$, which makes the cost for its lifetime maybe 0.0012 US$/printed page. So its really a small amount when taking the average lifetime into account. Everywhere where people have to print a lot, like e.g. banks, insurances or government agencies you will most likely discover either Kyocera or Lexmark laser printers.
First you may think, if you really need a printer of your own.
If you are not willing to pay say > 400..600€ for the thing, you don't really need a printer, because you have too few printing to do.

Then you'd propably better be off with your copy-shop down the street:
high quality hardcopies, lower price per page (many underestimate that even the price per one b&w-page of a "low-budget"-printer is quickly above 1€ (color may be over 3..4€! - per a single page!) Not counting failed prints because of blur, wrinkles, or cartridge went empyt while printing)
In a copy-shop you only pay, what you get,
and no fuss about those hobbiest-home-"office"-printer-crap aka waste of resources.

Otherwise it's very likely in 2..3 years your new "fantastic-five-thumbs-up"-printer starts having the first troubles again.
It's not the printer was old, it's they are programmed to start to fail, to urge you to buy a new one (and switch to new cartridges, of course.)
Of course, the new one is "greener". Saves 90 mg CO2 (but cost 3.5 t for production, transportation and disposal! [search for pictures of electronics-dumps in Africa; you may point out to some scrap printer:"Hey, I once had the same one, too!")

But the worst part is,
you're wasting (your) live-energy by getting annoyed about a printer that is neither damaged nor old.

3 times HP
I also had a Scanner and several computers by HP. They are on my black list. I had one of those famous DJ520, once. I loved this thing. Exemplary! But then they simply discontinued to produce the cartridges. The last one was a b&w-laserjet. I trashed it in the recycling bin after the third page, which took me a whole saturday to get this shit doing even that! A few days ago I read on HN that HP "upgraded" their printers to not accept third party cartridges anymore. Or they simply discontinue drivers. So you'll end up dumping a piece of hardware, only few years young, which could continue working properly, if there was no greed in the world.
To me HP is dead.
Then Konica-Minolta really p133ed me off, also with a rip-off customers mocking-policy.
See the video Jose linked above.
I once threw a printer out of the window of the third floor! Felt good to sweep the cobblestones afterwards; I can recommend that (ensure the street is clear first!)

So I made a little evaluation process, which preced the realization that I don't will buy any cheap "home-office"-printer anymore, ever.
So I was looking for a professional one.
So I decided for to give Ricoh a try.

professional, Postscript, network, Color-Laserpinter, duplex,.... cups (I don't use cups, but there are many Ricoh printers on the list.)
not really low-budget when buying, but lowest on price per page

Search the internet for cent/page per printer comparisons.
Those 149,99 are the very most expensive ones aka cr#p.
And those comparisons only respect producer's specs, not that the printer will start showing the first troubles after 150...300 pages and behaving old and damaged long before specified life span.

My Ricoh now is in service for over 12 years,
still printing its couple of pages per day, or sometimes a handbook in one job at once,
no paper jam yet so far,
especially no "paper jam", when there is no paper jam, no mocking with empty cartridges still halffull, not telling me it cannot load paper, when everything is just perfect, ... not starting doing like being old when 3..4y, and after open it, everything is brandnew - not p133ing me off!

no (additional) grey hair anymore!
simply prints.