Korg Monotron Duo Analog Ribbon Synthesizer Modules $46 + Free S&H

Price: $45.99 (Reg. $69.99) Shipping: Free. These have shot up in price lately (MSRP is now $70 at Sweetwater/Guitar Center), so getting it for under $50 is a solid deal. This is the Duo version, which has two oscillators and a scale function, making it way more "playable" for melodies than the Korg Monotron Delay version. The Good: Real Analog: Uses the same VCF filter circuit as the legendary Korg MS-20. Dual Oscillators: You can tune them in intervals for thick leads or fat bass. Actually Playable: Has a button on the back to lock the ribbon to Chromatic, Major, or Minor scales (so you aren't just guessing notes).