I'm here using Rim War for some better world interaction (it allows you to capture settlements, causes raiders/traders to actually move across the map, declare war without having to shoot a guy 20 times etc. etc.).
But yes, do wish the VE vehicles were cheaper. It's easier to just buy out every vehicle part you can when you get a trader than it is to actually make them.
Honestly, I don't think making the parts is the part I dislike the time sink for -even though I do think mods that make you craft individual components like VVE makes you are annoying nonetheless- it's the fact that it ALSO takes like 600 steel on top of the 200 or so you put into parts + a dozen and a half components spread across the building and the parts.
Like, I would honestly say subtract the vehicle's cost as is from the cost required to make each part, plus maybe reduce the time it takes to make it. Otherwise it's late game. I've honestly found more utility from SRTS even tho it does also have the issue of it being a giant resource sink, but then again, I've also found SRTS to have more utility than VVE vehicles sadly.
By the time you get a chance to make a combat ready vehicle, you're facing like 50 people raids, and/or you're attacking settlements. Though that does tie back into the fact raiders in Rimworld just kinda have one strategy, that being monty python charging at your guys. Maybe if larger raids set up camps and did more harassment skirmishes than giant assaults would be nice.
...though if i were to design this, i'd make the current siege mechanic a bombardment raid or smth that is time limited OR until you break it up, and a siege sets up a permanent base on your base and harasses your colony as above on top of preventing ground traders and visitors from entering the map.