Diesel or gasoline, transmission, etc and costs – benefits/disadvantages?

Good day, I am currently looking for a new or used car as a replacement for my 12 year old Nissan Primera (diesel, 120hp). Now I’m also thinking about what kind of motorization or what I’m actually looking for in detail. I’m most likely to like an Audi A3 saloon as a diesel with 150 (better even 184) hp and that as a switch. If I see this right, then automatic (or in the case of DSG) gearboxes have better convenience, but also higher follow-up All 60.000km have to be there, so I read it, gear oilwechstel take place, which already costs a few hundred euros. In addition, they can also be more vulnerable than normal manual transmissions and a repair is there much more expensive than with a formwork transmission. Since I drive manual transmission anyway, I think it might be useful to continue to poking on it. Nevertheless, I like to read other opinions, which may not seem like a no-go for me. Then I also ask myself what it looks like with diesel against petrol. The costs in purchase and tax (higher with diesel) compared to cheaper in consumption and tanks (with diesel) I already know. On the other hand.. what does it look like with soot particle filters or other follow-up costs? I think my primera should not have a soot particle filter and therefore there are at least no high follow-up costs for replacement or cleaning . Is just a dirty sling with a high tax and also old. But also with regard to the big anti-diesel debate by the media I am a bit unsure. Would I also be happy here if you could tell me something more conkter here. Otherwise: Do I have to know something else, what I don’t know at all?