I can certainly see a Warhammer/40k player being distinct from a Miniature Wargaming player -- every new one you take on is a lot of $$$ right?
As someone who self-defined more as a minis gamer than a roleplayer for many years, that isn't entirely true. You can certainly spend a lot of money on a new game, sure, but there are lots of options that won't cost you anywhere near as much. The costly stuff is either GW stuff (which is simply overpriced because they can get away with it) or rule sets that call for large (often triple digit) numbers of models, the latter of which are frequently historicals from an era where blocks of troops were the norm and the figure-to-manpower ratio is small so 20 figures only represent (say) 200 men rather than 200 or even 2000. There are other exceptions. Games that call for very specific, elaborate scenery drive costs up, and there's enormous variation in price norms even within the same genre and time period - historical figures are generally cheaper per model when compared to the same scale of fantasy/scifi, but (for ex) Old Glory historicals are much cheaper than, say, Artizan's are.
But those high-buy-in games are an exception these days, not the rule. "Skirmish" or "warband" gaming has expanded a lot since 2000 or so, and there are hundreds of them on the market now. Most only require a rulebook and 20 or so figs per player, with many only needing a handful of models. Those are generally pretty inexpensive, with buy-in as low as $30-50, easily on par with RPG costs. Even GW keeps their small-skirmish games down in the $100-200 range, and that's mostly due to high starter box pricing. Moreover, many rule sets are designed to work with as wide a range of figures as possible rather than being linked to a bespoke range, so you can often use things you already own in your new game system - including ones you've 3D printed yourself at home, which is stupidly cheap once you have teh equipment in the first place.
One of the bigger successes in the last few years was a Car wars-style game called Gaslands that was specifically designed to work with toy Hot Wheels cars (which cost less than $2 most of the time and are often found on sale) that you've converted by gluing on some weapons and armor plates. You rarely needed more than a few cars for that, so you could get what you needed off a $30-35 rulebook and maybe $10 worth of figs - or for those with kids, by quietly looting the toybox. The fact that it also played well helped, but the low price tag was a big draw too.
It's definitely one of those hobbies where the more stuff you've accumulated for it over time, the less it costs you to expand further. The initial cost of painting supplies and a rule set and figures for it is steeper than most RPGs, but from there on you can often pay less going forward by using your existing collection. Does tend to take up a lot of storage space though, especially terrain pieces.
Minis are really only a super-expensive hobby choice if you buy into GW's nonsense about
being the hobby. They aren't, any more than all roleplaying is D&D. There are minis rules that fit just about any budget and set of interests out there, just have to find them.