Well, I wasn't going to comment, but some of my friends are chiming in, so why not. I can tell you that my York budget alone(for attending only once a year) generally is around $2,000. Typically I do have some change left over, but whatever is left of that is added to whatever other train show that I would attend after York. I have had it where I went to a few train shows one year before going to York. I believe I had spent just on the train shows about $1,500. Now, if you were to include what I bought at my local train store, that year alone, we're talking maybe $7,000 there or maybe a bit more. It is hard to say because as it has been said, things vary like income, time, and also most importantly, what your interests are.
That being said, I have sort of slowed down a bit, nothing like when I was in my 20's quite some time ago. Granted, those were easier times on my body, but just about the same on my wallet. Regardless, I have dialed back some spending, and have only selected a few things to pick up here and there. I am also concentrating like some do on some older stuff for upgrades(meaning buying new older engines to be upgraded). I do have a list of engines I have that will be upgraded eventually as well.