The Moog Werkstatt-01 can be found for $200 or less. Introduced in 2014, it comes disassembled as a kit that just requires a screwdriver for assembly. The components pretty much just snap into the board without soldering. It is a patchable analog synth that can be sonically modified with jumper cables, a CV Expander, even an Arduino microprocessor. Small round buttons on the bottom row of the device act as a keyboard.