Is the conversion on LPG worth it

Hello, since a switch to another more economical car doesn’t really work and I would also miss the “luxury” (I mean the driving feeling ^^) of the big one, I think, whether it makes sense to switch to LPG. My father thinks that it should not be worthwhile with my car, because 129000km are already a lot for a car. You can argue about it ^^ Well. At the moment I drive only to the 30km plus at the weekend again 200km. That’s just ~1500km a month. That would be a yes However, it can be (therefore also the consideration) that I will commute from Hamburg to Bremen from October for a year, which would be 200km daily. That would be a monthly output of about 4400km or to the year ~53000km (extra driving not included). Purely from the caclulation it would be worthwhile with the number of km already, after the year the money would be almost again. But what also gives me something to consider… 130000 are not so much… but I once read that automatic transmission does not last as long as manual clutch… what do you think? Greetings rags