They include FOB to the nearest truck terminal in the cost. I always look at shipping charges first because 90% of the time that's the deal killer. If someone is trying to be slick they'll low ball a price by not including shipping in the online price.
Also they claim 4000 cycles at 50% DOD. That's 11 years every day to 1/2 capacity. If that's true I would expect them to be worth more. They also sell them as 2v units, so their main buyers are probably telcos and power companies. Ten year warranty with 7 year free replacement would cost something too. Those don't sound like something the casual RE user would be able to afford.
They add telfon threads to the paste to strength it and the positive plates are heavier than the negative plates.
You might be able to get take outs. They have a payback offer of 15% of the original purchase price if you trade up for new batteries after 5 years. That means you don't have to oversize so that you will still have the necessary capacity at the end of the ten year useful life. They look like they are out of my price range.
