That one there is $50, but like I said, its a dual splitter (both power and ground). Cheaper no name splitters can be bought at your audio store though, I think my power (2 guage inlet, 4 fuses, 2 or 4 guage outlets) was only $25 (you only need a 2 outlet splitter though) and my ground (2 guage inlet, 4 x 4 guage outlet, again, you only need a 2 outlet splitter) was only $15. Also, for reference, that one has a 4 guage inlet and the outlets will hold a 4 or 8 guage wire. 
I can't really tell from your picture, but is the purple wires your speaker wires? If so, it looks like they're a 10 or 12 guage wire, which is good, bigger wire means better power transfer. Also, check the wattage of your subs. With your new amp, you may find yourself blowing one or both subs, but thats good, as they don't look to be that good of quality anyways. When/if that happens, i'd suggest going with a cheaper, but brand name subwoofer. Stay away from Sony Xplode crap, as i've learned from the past that they can't handle the power they say they can (I blew two 12" Xplodes in less then a week in my first car with an amp that had an RMS power of less then both subs RMS rating combined). A good cheap alternative would be a set of Pioneer DVC (dual voice coil) or single voice coil 12" subs. I've found in the past that they will handle the wattage they claim, and can usually be picked up for under $100 each, and come with a 1 year warranty.
Any more questions, feel free to ask, and if you need one, I might be able to draw you up a wiring diagram sometime this week when I have some free time.
Found this on the site. This is sort of what my ground wire distribution block looks like, only mine is gold plated and accepts larger diameter guages.
This particular one is $20, but again, you should hopefully be able to find something cheaper in your local audio shop.
And for reference, when i'm talking about a fused splitter box, this is what they look like:
It gives you added protection on your power wire by adding an additional fuse in line from the battery (make sure to still have the power wire fused within 1 foot of your battery though) and the extra inlets allows for the addition of a capacitor in the future, aswell as different mounting locations (power in from the left, center or right of the block, which comes in handy when you start running out of room like I did).