I don’t see anywhere where they are way cheaper. Are you looking at the marine versions of the lithium banshee? They look about the same price with a 2 year warranty. To me that sounds horrible. Look on bass boat central. Bass guys have a lot electronics. The 100ah Ionic with Bluetooth with are about the same price with an 11 year warranty. With the Bluetooth app you can go multiple days without charging because you know exactly how much power you have. Plus it’s best to store these batteries between 40-60% for extended periods. The banshee you aren’t going to be able to do that.