The circuit boards could be made of diamonds and Legacy still wouldn't be worth $200-300 more for a similar locomotive, and added details are just a spot of cyanoacrylate away. Maybe if one was all die cast metal vs. plastic, and one had no sound whatsoever, or was grossly misproportioned vs. scale, but I can't justify the difference. Can you convince me one is better? Surely. It's a matter of diminishing returns.
Even if you run command only, it seems to me you can add ERR circuits for much less than $300.
