Welcome to the Forum from Germany.
I also recommend the K-5 or K-5II.
It was the first Pentax camera which offered roughly the resolution of ISO 100 24x36 film.
Dynamic range is not yet up to modern color negative film, but well into color slide territory.
For your purposes (and your budget) I would not recommend a K-30 or K-50, despite they are using the same sensor. The K-5 was the flagship in its time, and Pentax always cared much more about reliability of these, compared with lesser models. Failures seem to be MUCH less often than with K-30, K-50, K-S1, K-S2, etc.
If you don't need the camera within the next 4-5 days, on German eBay you would be able to get it for about €200 (body only), with less than 10000 actuations. You'll likely also need to spend some money for 2 SD cards and a reserve battery.
K-5-II is still €260 - €320.
And I did explicitly mention "German eBay". I am several times a week searching eBay with the option "Europe within 2000 km distance", which includes nearly all of the EU as well as Ukraine, but only the most western parts of Russia (I have all the russian lenses I need).
With this kind of searching I got the impression that used Pentax equipment from Italy (and also from Denmark, Belgium, and Switzerland) is offered at start prices 30-50% higher than from German sellers (France and the UK is about the same as Germany). Not to mention the exorbitant transport cost from Italy to Germany - ridiculous, it's nearly as expensive as from the USA to Europe.
So I suggest to look also for offers from all EU countries - no duty troubles and very seldom problems with sellers where eBay would not help you.
My experience.
Good Luck!
---------- Post added 21-08-18 at 22:05 ----------
Originally posted by Bethor You should also check out the for sale section here. A lot of other users have had great luck with it.
The OP is located in Italy.
Transport cost from US to EU (insured) are very high, and despite a used camera body would likely not cost duty fees, italian customs may still stop delivery and have a look at it. If unlucky, you then have to drive to the next big town to get your package.
I know why I am not using the Pentaxforums marketplace.
And it's also the reason why you will not find many European members using it.
It's just too expensive, and returning it if something is not ok sometimes can turn into a nightmare.
US customs can be worse than the Swiss (and that's difficult!)