With $500, I would first purchase a Playstation 3.

The PlayStation 3 (officially abbreviated as PS3) is the third home video game console produced by Sony Computer Entertainment, and the successor to the PlayStation 2 as part of the PlayStation series.

A major feature that distinguishes the PlayStation 3 from its predecessors is its unified online gaming service, the PlayStation Network, which contrasts with Sony's former policy of relying on video game developers for online play. Other major features of the console include its robust multimedia capabilities, connectivity with the PlayStation Portable, and its use of a high-definition optical disc format, Blu-ray Disc, as its primary storage medium.

The Xbox 360 aside, the Playstation 3 currently stands as the most advanced consumer-level gaming console on the market.

The APC 40 is a MIDI controller that is used in conjunction with an electronic music production and performance software Ableton Live.

"Ableton Live software is a powerful, flexible environment for creating, performing, and producing music. This unique software demands an equally unique control instrument. Combining the APC40 with Ableton Live transforms the user experience from constructing tracks on a computer to fluid, musical creation and performance.

The APC40 is the link between human and computer that perfectly balances analytical parameter control with creative expression. Whether you are an electronic music artist and Live is your canvass, a DJ using Live to mix or remix tracks, or a more traditional musician using Live on stage or in the studio, you will find the APC40 to the intuitive, powerful instrument that directly links your inspiration with Ableton Live."

- http://www.akaipro.com/apc40