Hi Croix,
I am still loving my LiFePo4 batteries. I have to agree, the route I went was very expensive. That was due to the high C-ratings on their Lithium cells. For RV use, high C-ratings should not be required. Even my max draw rate probably only uses a small fraction of the battery's ability to deliver current. My thought was by using such a small percentage of the battery capability, I would be extending the cycle life of the battery cells and end up with a pack that will last me a very long time. Time will tell if am correct or not.
I expect with a little searching, you can find a quality LiFePo4 battery pack that is say C5 rated that would be half the cost. It would still be a lot more than AGM batteries but I feel they are worth it in the long run.
Mine have worked flawlessly for over two years now. There several Karavan owners in Australia that have switched over to Lithium as well. That is where I got the initial idea. Reading about their experience matches mine and they are all very happy with the increased power and what appears to be a very stable long term battery solution.
Thanks for the kudos on my photos. I get a bit carried away with it.