Save up for it! It's so much fun. :D
Until then there is VCV Rack which is free and loads of fun.
Most eurorack modules don't use the 5V so it's common to only use 10 pins. But all eurorack busboards are 16pin if you need the 5V. That's why most ribbon cables for eurorack modules will be 16pin to 10pin.
i really wish i had money to build myself a modular :_(
anyway, out of curiosity: what's the difference between those two connectors - is left one missing +5V, CV and gate?
i'm sure it is! :D
thanx for an answer