Changed mine in march at battery centre, paid about 900.00, the good thing is that if you have a problem, you can go to any battery centre nation wide, it's an excide battery..
Ok thx guys. So its looks like I'll spend about R1k at least for an oem spec type from battery Centre or the likes.
I did a trickle charge on the deltec, which is exactly 5 years old, it charged up halfway only and didn't hold for 24 hours. The yellow top batteries are a crazy R5k so I'm definitely not getting those.