Would this work?
I very much doubt it.
ECML took me the best part of two years worth of my free time to make. Let's say I could have completed it in a year, if I worked on it full-time, and that I had built all the objects myself, without using anyone else's work.
To recompense me for a year, I'd need to earn roughly £50,000 from it (living expenses, travelling, computer outlay, etc). It's been downloaded about 3,000 times. So, each person downloading it would have to pay me about £17 for me to break even.
Then, of course, you need trains. I'm sure that, if some developers provided trains for free, they'd get a bit miffed if route builders sold their wares; so you'd need to buy the trains, too. I don't know how long it takes to build a train, but, taking into account having to collect sounds as well as images, it's going to be time consuming. So I'd expect each train would cost about a tenner - but you could expect to use it on more than one route, I suppose. ECML uses eight trains - let's suppose you have eight other routes you can run them on, so let's attribute the cost of one train to ECML, so, so far, the cost is around £27.
Which means, to own eight routes and eight trains, you're going to spend £216. And, let's say that your favourite developers produce two upgrades a year, you're probably going to need to spend £216 every year (after all, in this scenario, a developer's got to make a living!).
And that, of course, presupposes that the likes of Mackoy, Reschanger and plug-in developers don't start charging for their work, either.
Let's say that the 3,000 downloads of ECML actually represents the entire worldwide BVE community (for ease of the maths - although I suspect that that figure is high, as the downloads includes the upgrades), then you've got a BVE "industry" that's only worth £648,000 a year worldwide. That would just about support a total of thirteen developers. Let's say half of them do trains, and half of them do routes, so you can expect to see only six new routes a year FROM THE WHOLE WORLD. The "volunteer" community is capable and prepared to produce more than that FOR FREE - there's roughly one new route, or an upgrade to a route, every month on average.
The whole ethos of BVE is that it's all copyrighted freeware. Let's leave it that way.
Regards
eezypeazy