This little wunderkind should be everyone first step into the very deep hole of modular synthesis. The hole is deep and expensive, but at around $500 US this very capable tiny semi-modular will keep you busy for a long long while.
Moog Mother 32
Here are some facts:
Huge Version of Infographic: synthWaves.audio/Moog/MoogMother32.html
QuickStart: Moog MOTHER-32 Quick Start pdf
Manual: Moog MOTHER-32 manual pdf