The older I get the less interest I have in watching big aggressive fish whaling on each other in an aquarium. I like to go into my fish room and enjoy a relaxing spectacle of fish...big, small or a mixture...going placidly about their business in a quiet restful tank. Having a pair of big cichlids frenetically herding around a school of plankton-like fry, keeping their surviving tankmates herded into a corner of a tank that they've completely dug up and re-arranged, gets old after the first few times...never mind the first few decades...
I know a lot of folks like to try a new cichlid species, get it to breed, wind up selling or giving away the young, and then move on to the next functionally-identical contender. Especially since moving into my current relatively-remote locale, I just can't get into that mindset any more. I've run through that cycle a few times up here and it just seems so silly to scuttle home from the LFS...which is just over 100km away, so maybe it's just the FS...chortling and rubbing my hands together at whatever new "challenge" awaits in the plastic bag. Fast forward a year, and I find myself using the offspring of that must-have species as feeders, and maybe bagging a few up for a local...again, 100km away!...auction, where they will bring in less than the cost of gasoline to drive the round trip.
I will definitely "stoop" to shrimp, livebearers (including guppies), Medakas and other small species. Even the lowly Goldfish has cast its spell upon me; big, colourful, active, peaceful...and, yes, another insane breeder if you still like that sort of thing. They even make good (dead) bait for fishing!
Finances? Well, this hobby can be very expensive...but it can also be done on a shoestring budget. For example, we live on a planet that is 70% covered with water. In many or most places, you can dig or drill a hole in the ground and it will fill with water. So...if you select species that will live in that particular flavour of water, then the primary ingredient for success is available very cheaply, almost free in many cases. My water costs me whatever trivial KW-hours my well pump consumes, and despite the fact that it's so hard that it's almost crunchy, there are lots of fish that like it just fine. If I decide I simply
must have some picky species that needs soft, acidic water, forcing me to manufacture it in my home with RO or whatever, well of course it will cost money. I especially get a chuckle when I read about somebody reverse osmosing a batch of water for their fish...and then buying minerals to add back into the RO water to actually make it usable. But doing that just seems to be not only wasteful but also a very inelegant solution to a non-existent problem; to each his own.
Fish keeping is indeed a luxury rather than a necessity. For that reason alone, it is exactly the sort of thing which will be reduced or cut out completely when economic times become tough.