I think I'm lucky in that I have a good used equipment LFS near me and hope to buy stuff on the cheapish. The thought behind the 75 was not that it was the end stage, but rather to see if we want to maintain a larger aquarium, and it had dimensions that fit a space we had in mind.
What we think we want is in the 300 - 360 range, so it could be used as a room divider. I own a split level, and we have a 10' opening between my living room and kitchen, with my living room 3' below my kitchen. There is a banister there now, but as a WoodWorker, I want to build a stand in the living room, so the tank sits about 6" above the kitchen floor and 3.5' from the living room floor. Then have a tank 7'(ish)x2'x3' replace the banister. The room on the sides will be finished cabinets facing both rooms and pendant lights from the ceiling. This maintains the open view.
Building it will not be an issue, I love building stuff (My beardie has a 6'x2'x2' wifi controlled smart enclosure). As my wife says it is maintaining what I've built that I struggle with. So this one is a biggie and we are taking it a little slow.
