Having more or less abandoned digital gaming in favor of tabletop gaming, and not having time to buy/read new systems, I control my spending by basically having free or at least very cheap hobbies.
More seriously, my primary hobbies these days are cooking, concerts, and tabletop RPGs. Digital media comes in a distant fourth in terms of time, though it’s probably the priciest thing overall.
Cooking is a de facto cost, insofar as my partner and I need to eat, and even with the occasional kitchen gadget purchase, we spend way less with me cooking for us than we would eating out more often. In fact, since the overwhelming majority of my pricey kitchen tools (stand mixer, Indian mixer/grinder, food processor, slow cooker, pressure cooker, my best knives, most of my serving utensils, most of my pots/pans) have been gifts or were inherited when we first moved out, the cost is almost entirely just ingredients, so alarmingly close to $0 “unnecessary dollars.”
Concerts are my personal largest non-essential expense by a pretty wide margin. However, since most of the bands I like aren’t especially popular and tend to play at really small venues, the average ticket I buy is about $10-20. Even seeing an average of two shows a month, this is a relatively small cost over the year. Probably about $300-400 total each year. Especially since even the ones that are far away are carpools where the gas costs are shared.
Tabletop RPGs are cheap once you own the books, and since I mostly run and play the same handful of systems, none of which have very many splatbooks, this hobby has become extremely cheap. Sure, back when I was kitting out my Hero Lab license with digital copies of two dozen Pathfinder rules supplements to let me easily build crazy monsters to challenge my players with, I might spend $20-30/mo, but nowadays, my expenditure is essentially zero. About once a year, I have to buy new dry erase/wet erase markers (for my whiteboard for notes and vinyl gaming mat for maps) and sets of note cards (for quick notes to players/Fate Aspects), but we’re seriously talking about like $15.
A couple of times a year, I’ll splurge and buy a new digital rulebook. I bought a set of dice last year for a new game I was going to GM (a big bag of mismatched d10s). Total RPG spending year-over-year is probably $100 tops.
Digital media is probably the priciest thing total. Between Netflix, Hulu, Google Play Music/Youtube Red, and my Dropbox subscription, we’re on the hook for $55/mo, give or take, which technically makes it pricier than the concerts. But since most of these are shared/required by my partner, and she splits the costs with me, it doesn’t hurt that bad, and isn’t entirely my choice to make anyway, hah. A lot of months I may only use the Play Music and Dropbox portions of this
Bout $700-800 out of my own pocket for a whole year’s worth of hobby joy, including an average of 2 RPG sessions/week, 2 concerts/month, 10-12 homecooked meals/week, and enough bingeable TV to keep my entertained during any remaining downtime :)
TL;DR: So, ya know, somewhere in the ballpark of $60/mo in actual hobby spending. Which isn’t a tiny amount by any means, but now that my gf is working and more than doubling our household income, it’s also very affordable. We put the remainder into savings/paying off our debts.