4x5 isn't really too expensive.
as others have suggested, it is a little different using
sheet film, and the cool thing about using a large format camera
is that you can expose things like lith film, paper, and xray film that costs
very little, and for a few dollars you can process it yourself and do
the whole mad scientist thing.
as jason said, it is cheap entertainment ...
but i can understand the whole processing thing isn't for everyone ...