I dropped out of school when I was obsessed enough with Max and render engines, spending 12-14 hours a day just testing every area. After some time I started getting contacts via the forums where I had posted my renderings to share with others.
The biggest problem that I faced was a long time that is required for a computer to process renders. The obvious solution will be to develop the hardware and buy new hardware, but I also use online render-sites as well.
Lot of my inspiration comes from various architectural websites. All the time I try to keep up with the latest projects and news in area of architecture and engineering.
Here in Brazil the market is heated, there are times with more and less demand. Marketing activities, and a little creativity when it comes to advertise the product are essential.