There’s almost always savings to be had if you look out for used gear on whatever your equivalent to Facebook marketplace/Craigslist/etc. another place I’ve had good luck in the past is with species specific forums.

Years ago the P-Fury board always had factory made and diy equipment for reasonable prices, and tons of people to help you design a custom tank/stand/etc to fit your space, budget, and fish. Actually I wonder if that place is still around…

But yeah, deals are always around, it’s just a matter of being in the right place at the right time. Friends, relatives, colleagues, that are into the hobby will probably have gear they no longer use or will upgrade or even vacate the hobby and sell the leftovers for great prices.

A friend of mine had run salt tanks his whole life and suddenly decided he wanted to take up playing pool and try a planted freshwater tank. He gave away $5k+ in saltwater equipment to a friend of ours just to help move the old stuff out and the pool table in.

Fish keeping is just one of those hobbies that’s always going to see evolution in setup so there’s usually a pretty good flow of used equipment in market places and almost always a buddy with more stuff than they know what to do with, happy to help out a friend.

And if you’re looking for new equipment I almost always recommend looking at diy options. There’s more information than ever on the web for how to build everything you asked about in the OP. I’ve found there’s often a pretty close relationship between the cost of DIYing something and buying used. It just depends on if you have the time/desire/tools for diy or whether you’d prefer to buy from someone/somewhere.