Years ago, before I got into this hobby myself, I set up a "nemo" tank for my nephew/godson. Little Nemo and Dory (a blue damsel) lived for years, in a little boy's room, without too much maintenance. They may have lived longer than 5-6 years if any of us knew what we were doing. Heck.... "serious" hobbyists go through fish more rapidly. I've certainly lost more than two fish in a much shorter timeframe.
It was a 10g set up with whatever standard hood/light came with it, sand, and a biowheel filter. It even had (gasp) a plastic martian-like little cave, which was replaced over the years with a shipwreck, shark head, etc.... (whenever it got too yucky for my sister in law to want to clean it) LOL Heck, I use PVC tubes in my QT....a plastic shark head is more interesting. LOL
We added a few snails and hermits for clean up and added interest.
Then, when you have the resources to really launch into the hobby, you can just use the 10G for a QT.
Tracy