3D Printing + Model Trains

As harborbelt said, the printers have come down in price over the last few years.  Hobby level printers can be had starting at around $500 and can go up from there (the Flashforge Finder is $350 and gets good reviews).  The sweet spot seems to be in the $1,200 or so range for the well known brands (Makerbot, Flashforge, Dremel, etc).  

Filament can run from about $15 to $20 per roll, depending on the type (PLA, ABS, Hybrid, etc.).  I have actually found that a roll can last through about 4 medium/large prints, sometimes a bit more.  This is the reoccurring cost part of the hobby of course.

So, all in, a starter set complete with a few filament colors can start around $700 and run up to $2,000.  

So the cost isn't too bad.   The printing quality at these price points are improving from what I understand.  

Of course, if you want to get into the print quality that harborbelt has with his 3D printed cars, that starts getting into professional level products and that is an entirely different ballgame.