The one I have is also in black color. And you are right, these will require two batteries. The price you got is also ok. It was a bit cheaper in March - April, but now the prices have increased a bit.
You can get two smaller batteries instead of one large one. 110-120 Amps would be more than enough. When I last checked prices 135 Amp was for 9,700. 110 should be around 8 - 8.5k (not sure though)