Honestly, vehicles chew up SO much space they are mostly a non starter for me no matterbhow iconic they are.
I basically have a short list of the 'big' items from any given IP that I'd be willing to buy. And it's kind of a ranked list, so even if something is on the list, it won't get purchased if other large items on the list come out first.
Like, I've got the MTO Sentinel and I've got the MTO Apocalypse coming. I'm now capped out for large ML figures. For vehicles, I've basically allowed myself enough room for two more 'bike'-size things. Because there's no way I won't get Vengeance or '90s John Blaze. But besides that... no more large items or vehicles in ML for me.
G.I. Joe is a bit different because it's such a vehicle-centric brand. BUT, I've got the SnowCat and Arctic HISS both coming. And I'm getting the Despoiler because I need IG Destro. After that, I've basically set aside enough room/money for 4 or 5 more smaller-to-mid-size items and one plane (the Conquest, if they ever do it). After that, I've gotta call it on vehicles no matter what they make.
For Black Series, I've always said I do my utmost best to work out the space and finances for a Black Series X-Wing. Besides that, I want to re-buy the Dewback if they ever release it with the newer Sandtrooper body, and I'd like to eventually get a Tauntaun if they ever release a Luke that doesn't have embarrassing articulation (no fucking WRIST joints, Hasbro? Seriously?). After those, I'm probably out on any large Black Series items as well.
Maybe a speeder bike and/or a swoop, if they (re)release either of those.
And even then - if Hasbro does ALL of that stuff over the next few years, I'm fucked and it'll be a nightmare no matter how responsible I'm trying to be with limitations.