Hi, That seems like a really good price. I have a LiFePo4 30 Ah battery which cost me $400 last year.
http://www.batteriesdirect.com.au/sh...deepcycle.html
Maybe I got ripped off, but the battery in your link seems a very very good price for what you are getting? It's also extremely light as my 30 ah weighs 3.3kg, while that is twice the capacity but still only 4.4 kg.
Cheers
Paul