Hi Ryan,
I've been away from the world at large for the past few years due to health issues but I am back now and fast catching up on what I have missed.
I only mention this because my data on LiFeP04 prices and packages is a little dated but I don't think my knowledge of the tech is. LOL
As I am researching a dual install for our FZJ80R and one for the camper trailer I will add US prices for cells or vehicle batteries and post them for you.
In short you get approx. a 40/50% weight reduction, faster charge rate, use your current alt. etc, longer more stable rate of discharge, no acid in the vehicle, higher usable capacity for the same volume or the same usable capacity ie. output in a smaller lighter form. Forgot to mention the self discharge rate is miniscule compared to l/a batteries.
I posted [along with many others] for a few years on nautical tech. forums about the real life performance of LiFeP04 and got so sick of the lead acid lobby and their misinformation that I stopped posting altogether.
IMO the tech is much, much safer than acid filled batteries and is my pick to install both as a starting and storage/winch battery for efficiency, safety and significant weight savings on my vehicles.
The cost should be reasonable and nowhere near the $1400 you've seen!!! Not even in that ball park.
Here's an old marine link I used to refer sailors to.
Lithium Batteries
They're using bigger than what you'll need but it may be useful to you to see how simple and safe the batts are and for weight/output comparisons to various l/a types.
The cells are usually regarded as storage but they are equally adept as starting batteries.
General information:
Liberty Batteries Why LiFeP04
This is the short version as there are thousands of pages of info out there from users and I'm trying to save you time in getting the basics. LOL LOL
Cheers,
Paul