'ME-Models' markets metal tracks that substitute Lego's official 9-volt track, and 4D-Brix reproduces 9-volt monorail substitute parts (including track, motors, plus battery packs) as well, so why has nobody stepped up to the plate and tried to recreate/mass produce motorized 9-volt train bogies/trucks (serial number 590/70358)? A mint one currently goes for as much as 70 USD and used ones go for almost 40 USD, which is ridiculous since that's enough money to buy me food for a week.