I got into model making when I was 4 years old, when my parents did most of the work on the ANH Falcon kit that came out. Dad did the grain of wheat bulbs, mom did the black washes, and I helped cut things from sprues and glue (I kid you not - hippie parents giving their child a hobby knife and that Testors glue!)
From then on, until I was probably 13, I built models as my primary hobby. Mostly from the box, and mostly to hone my skills. It taught me patience. It taught me spatial relations. I got better, and towards the end of that first run of building, I started scratch building, turning a Ferrari Testarossa into a hover car. I remember using SPACKLE for filler!!
As I became a teenager, those models became vessels for fireworks, and I was more interested in playing music and chasing girls. Around my senior year of high school, a friend wanted to make a "space movie" and I started making miniatures for him and it rekindled my love for making models - and scratch building/kitbashing. There was a scene on a "lake" and we blew up a model i made - I took a Polaroid still from the TV we were screening shots on, and it's the only photographic proof I have of this time in this model building phase:
Kablammo | Flickr - Photo Sharing!
In College, Galoob and Hasbro started releasing Star Wars toys again (1993/5) and I started collecting, modding, and really becoming obsessed with Star Wars again (Those Zhan books helped in High School, too). The internet was a new gateway for reference pics and opportunities to connect with people, and find things. I realized in 1999 (via the R2 Builders Group) that people were recreating props! Found the RPF shortly after that, and dove in head first.
I never looked back.
Because of luck, skill, timing, and the internet/RPF, I have been able to make replicas for good money. I funded our wedding, helped buy furniture when we bought a house, helped keep up with repairs, took us to Japan to sell kits I created, and I have folded money back into the hobby for big zany projects. The friends and connections I have made here landed me at the Archives in Skywalker Ranch a good half dozen times, and I got to make things that were "official" - people own the Star Wars, Star Trek, Buffy, and Maschinen Krieger things I helped bring to market!
So to answer your question - I sell them. I continue to hone my skills. I even keep some of them (but everything has a price - I can always make it again!). For me, it's about building, painting, and watching the object spring to life on the bench. It's about the people all over the world I can connect with over the computer, or even in person if I am traveling.
Man, I'm in a good mood today! :lol