I would have thought that by now LFP has mostly overtaken FLA for home use. I can pick up LFP cells for just over $100/kWh, which is about what it costs me to get FLAs, but with far longer lifespan.
Anyway, that gives you 3.36kW of capacity (assuming a 12V 4S config) for $119/kW. To be fair, it will be slightly more when you price in your BMS of choice.