For many years I bought cable just to watch the fights (USA, ESPN, HBO Showtime, then) and every pay-per-view. And for every fight I had people over, and that cost money, too. And I taped every fight for a very long time. And I was a member of the Forum Ringsider Club for years and before that I sat ringside for the fights at the Forum for quite some time (though, to be honest, a business associate comped that).
Then you get into the gym in my garage, which I updated as fast as Ringside came out with new product. And all my friends had gyms in their garages, which I paid for. Over the years I've supplied handwraps for maybe 150 kids, not to mention picking them up and driving them to the gym. In the old days you used to have to buy video of fights (no youtube!!) and I've had many stolen from me. (boxers are ok; MMA guys cannot be trusted) At one point, around 2002, I had over $2000 invested just in fight tapes in my possession.
I've made numerous trips to Texas to watch particular fighters work out. I once made the mistake of driving an all original 1964 1/2 Ford Mustang, all original, top to bottom, to a gym in Riverside. Don't know what it cost me to replace the parts stolen off of it...
It adds up.