How much money on speaker cable?

My suggestion once you have the system in place is to purchase used cables for reputable sellers here and experiment. It's fun and informative if you don't mind selling the cables that don;t work in your system.
After using countless cables ranging from inexpensive Canare 4S11 to super expensive Straightwire Blac Silc I keep going back to Audioquest solid conductor wires. After JPS labs, DH labs, Kimber, Analysis Plus, and others I have settled on the AQ Slate biwired and feel no need to look further. Not saying they are the cables for you but speaker cables do make a difference and the only way to know which is best for you is to listen.

I'll second and third reccomendations for Analysis Plus and DH Labs as good bang for the buck and appropriate for your system.

I've gone from $1,200 Nordost SPM Reference to $300 Pure Note Cerulean speaker cables to finance a PMC subwoofer purchase. There was very little sacrifice in sound quality in swapping cables but a huge jump in sonics in adding the subwoofer. I would agree with the idea of not spending too much on cables and focusing more on components. $250 would buy you a good decent cable that should do well in your system. The rule of thumb is to spend about 10%-15% the total cost of your system on cables(which include speaker cable and interconnects).

I´d suggest you to try Evidence Audio Cables. They are made originally for electric guitar, bass or musical instrument amps. They sound very controlled and neutral and they are cheaper than the so called "high end" cables. This triggers an interesting question: Why electric instrument amps and cables, with the same complex or not craftmanship, are cheaper than "high end" equipment?

Defintiely check out Clear Day Solid Core Speaker Cables. Outstanding value and less than $500