I build open-source Eurorack modules, I can sell you some.

Nearness, In CV, Clock divider, MIDI 4+1 and AC+MULT are among joeSeggiolas most popular products.

Nearness

joeSeggiola

Minimal panning mixer

$63 MSRP

In CV

joeSeggiola

Terry Riley's "In C" implementation for Eurorack

$106 MSRP

AC+MULT

joeSeggiola

3x4-way multiple and 2xAC coupling module

$41 MSRP

Clock divider

joeSeggiola

Programmable Eurorack clock divider in 4 HP

MIDI 4+1

joeSeggiola

MIDI to 4x CV/gate, with polyphonic and monophonic voice allocation modes

6 HP MIDI