Smallest and most basic complex VCO: https://www.modulargrid.net/e/void-modular-gravitational-waves While it's missing a few controls you'll find on other complex VCOs, it's still very capable with its internal ring mod, plus you can use other modules to get deeper into the complex oscillator mojo...linear VCAs + an envelope source = oscillator signal that can rise after the note-on to alter the timbre across the sound's attack when you feed the audible oscillator the other oscillator's signal into the FM input.

Also, it's exactly $250...fits your budget perfectly.