Is a 9 gallon (18x15x8") plywood tank worth building?

[Hybridfish7]

I am planning on building a bigger plywood tank in the future, but I was thinking I could practice that by building a smaller one for now. Plus I like the idea of the compact look a little plywood tank would give if I painted it black. Is it even worth it based on the costs? Also what thickness of glass should I use for it, and what thickness if I used plexiglass instead? I was only planning on having one viewing panel.
If you're wondering what would go in this tank, I was thinking either a betta or shrimp.

 

[Gourami Swami]

Might be difficult to do such a small plywood build, and IMO not as worth it, since you can get a nice glass tank around that size so cheap. If you just wanted to practice with something small I'd probably goat around 20-30 gallons, would be easier to get your hands in to it to seal, install the window, etc.