Need help fast please

[xXsquintyeyesXx]

Last bike fell through. But talking to a guy about a 1997 gsxr with 30000 miles and paint peeling off around the gas cap. He wants to trade his bike to me for what's left of my sound system (2 12" memphis mojo cm cast D2, custom built to specs ported box, all wiring mostly zero gauge, and a shuriken btk-20 battery that rests at 12.6 volts) plus cash. I paid around $1500 for everything. I know most people on here don't like memphis but based on price value after only a week of use (they still aren't even broken in. But how much cash would you offer on top of my system. Thanks in advance. Please reply quickly because I don't know how long the bike will be available.