Jellyfish?

[Circus]

Luckily for me, a new glass framed 75 gallon tank was cheaper to buy ($100) than to make! No DIY on that one.

I don't think this is viable but they do make 6" Clear Schedule 40 PVC Pipe - 5 ft ($246)

It, or something similar, could be cut down (with proper tools and expertise, of which I have neither) to make several tanks. One to keep, two to sell and pay for everything else, lol.