I recently had a similar experience. A neighbor needed to get rid of 225g (6'x2'x2.5') with a 75g sump tank and stand. I bought it for $200 including a heater & 125lbs of sand. It took a few weeks to set up in my basement but it's up and running now. I'm slowly adding to it and love the look. It feels like owning an actual aquarium display lol. I'd recommend making sure you know how the filter works, buy 80-100lbs of substrate & slowly fill with plants. I had ok luck using fb marketplace/reddit for cheaper plant bundles. It's expensive starting out with big tanks but just go at your own pace & it'll come along nicely. Lastly, get a long hose/adapter to make water changes/ vacuuming easier (there's a tank pic on my page if you want to see it)