I'm interested in Bodenplatte, but I'm not too sure if this game is for me (Didn't like Il-2 1946 and CloD Blitz).

Is there a way to try it out before buying?

And are the 75% off sales also on the Il-2 Store or only on Steam (meaning I would have to buy Bodenplatte AND Stalingrad)

Wait for a Steam sale on Stalingrad. Buy it for $10-12. Then you have teh standard time Steam allows before returning if you don't like, I don't recall how long that is but you can look it up. That will give you a good idea if you like the sim or not, then you can decide if you want to buy any later additions.

I think it's the best WWII flight sim ever.

I used the 75 and 50's and bought Bodeplatte, Moscow and Kuban in one go at IL2 store last week so pure Bodenplatte should be a go.
You have to be an existing customer though but I think they add the promos a few days later if you sign up.

It is quite different to il2 46 and dover and would rather call it Rise of Flight 1943 but it a well done product and contrary to DCS these guys have a very high precision and quality in their releases.
Personally I like IL2 Dover better (skins and programming interface for C# for fun mission building) but if you dislike that one this could be your title.

GB sure have way better terrain, even better than DCS in my opinion.

GB has a career mode that is rather well done but to me the missions became repetitve very soon making me lose interest before finishing the Stalingrad career (both a IL2 sqn and a LaGG3 one) - will give it a new try soon in a P-47 on Bodenplatte when the new DM is released with the upcoming patch.

Only actual downside to me is GB mission editor, first time I tried it a few years ago I just walked away but have been giving it a shot again since my purchase and you sure have to micromanage everything - far from dropping a flight on a airfield and tell them to fly their route.

Overall product quality is way better in GB in comparison to Dover and DCS.

Edit: oh, and another downside is ground handling, you will not like the ground loops. Even complaints from an old testpilot that actually flew in the 50's has been ignored.

Edit 2: here it is: https://forum.il2sturmovik.com/topi...tion-in-bos/?tab=comments#comment-744347

Here is a much better dynamic campaign option than the stock campaign generator included in the original game:

https://forum.il2sturmovik.com/topic/19801-pwcg-810-released-better-configs-and-fc-stuff/
https://forum.il2sturmovik.com/forum/99-pat-wilson-campaign-generator/

The two best ones in the series, in my opinion, are Kuban and Bodenplatte. If I could, I would love to be able to uninstall Stalingrad and Moscow to free up some space on my external ssd. I don't fly the planes, and I don't care for the maps. But it all installs as one game so that isn't possible.
The Kuban map is outstanding, their best one. It's practically the only one I fly over. If you only want Bodenplatte you will have to buy it at the IL-2 site. On Steam, you have to have Stalingrad before you can buy the rest.