I've found the DCC discussions interesting. I'm also intrigued by the numerous advances in technology, such as with stationary decoders, sound, etc., which leads me to a couple of questions.
First, while I understand the basic principle of DCC, but I'm still unclear whether the heart of the technology's control side resides in the controller, or in the power-supply infrastructure.
I know enough about the technology to know that one must install certain power supply equipment, jacks, etc., and that one uses a handheld controller (usually) to operate the trains. And, depending on the size of one's layout, more than one booster may be required.
Now, I've been more or less aware of the DCC manufacturers' introducing new products, chiefly decoders with bells and whistles (both figuratively and literally), new capabilities, handheld controllers with new functions as features, etc. This is where my question regarding the "heart" of the control-side of the technology comes in.
Let's suppose "Modeler Smith" decides to upgrade the DCC system on his layout to take advantage of the newest capabilities, so he strips out the old and installs the new. What does he do with the old? Puts it on the used market.
Now I come along, and looking for a bargain, see his used DCC system and decide to buy it, as I'm interested in it.
This leads to a couple of questions. First, do "whole," i.e., serviceable, DCC systems, come onto the used market and if so, how frequently? (I know...it's not like trading in a used car against a new one.) Would I be able, assuming everything is in working order, to hook it up and actually run trains, all else being equal? I'm all for keeping expenses down wherever I can, so if I can snag a functional DCC system for a fraction of what I would pay new, I'm all for it.
Next, warranty issues aside, what are the advantages in buying a new system, such as Digitrax's Zephyr, to name one example?
Incidentally, I would use DCC on an HO double-deck switching layout of about50-60 aggregate square feet, which also features a branch line. There would be perhaps four engines at most on it at a given time, and the whole kit and caboodle would likely be one power district. I would use the simplest decoders on the market, as I don't need sound, nor the "special effects" so popular these days. Control and perhaps the headlights would be adequate. (Don't get me started on sound; I can recreate the sound effects in my head because I work on the railroad as it is.)
P.S. Please forgive me is this doesn't seemed focused at times; after all, I was writing this at three in the morning. :-)