You can enter medium format for under $1,000. I did. And that was for mint equipment. True, it was once a prohibitively expensive format to work with. Serious photography does not require "expensive, modern equipment" — at any time. APUG members around here are no doubt creating beautiful work with equipment between 20 and 60 years old, possibly much older, their investment being in knowledge and skill honed over time, not fancy equipment. That is the work of artisans who know their stuff and aren't so much carried away with equipment like, for example, Leica, which makes photography seem terribly expensive to people casually viewing it as a hobby. Large format can be expensive (e.g. a Linhof kit will still set you back a few thousand dollies); I avoided it for that purpose, among other reasons. It comes down to your skill in photography, the equipment is secondary, but it defines the shape and form of your work and the breadth of your experience; as with any format, you work with it, much the same as you see the world with your camera, and not just through it.