I recently got a message from the C&O Historical Society about an N gauge E8. Very nice, as seen in the insert below. Looking at the cost, It seems as if there's not much of an advantage any more in smaller trains. It looks like whatever cost difference between scales is, and has been disappearing. Granted the N gauge locomotive has upgraded electronics, but for the size, I'd rather stick to S. Looking at the American Models site and the cost of their E8s (which list around $280) it confirms my staying with the trains I like most. Now, don't get me wrong, I like ALL sizes of trains from Z to 1:1. I, like many other guys, dabbled in other gauges, including N, but I'm now forever in S land, for all its differences in flanges, track height, couplers and details.
S may not have the extensive offerings of other scales, but that's not just its shortcoming, but its draw. What isn't offered can be either done without, scratch built, or kitbashed. I guess that's what separates "model railroader" from "toy train operator". Even that is subject to one's own views. I know an importer of high end brass locomotives and rolling stock who sometimes refers to his trains as toys. That's a topic for another time, but it's been done before. I guess the bottom line is whatever hobby you have, including trains, is subject to a cost. That's why it's a hobby, not a necessity.
To illustrate my point on availability, a friend of mine wanted an E8 set in C&O colors. American Models doesn't offer theirs in C&O paint, so I custom painted them for him. Here's the result:
I recently came back from York, and thoroughly enjoyed myself looking at all the trains there, and even buying some small items. It's a great hobby, and like most, you can spend as much or as little as you wish, or can afford. Just enjoy what you want for as long as you can.