If you need a quick way to make money the sugar cane farm is just for that. If you are on a survival server or even on a skyblock server, you can sell your sugar cane for a high price.

2.5 may not seem like a lot, but if you have a full inventory of sugar cane (which wont be that hard with this farm) you will be getting a lot of money in no time.

This sugar cane farm may not work if your server does not allow observers to work, so I would test that out first.

The sugar cane farm is a pretty simple design, but a very efficient one. Sometimes the sugar cane might stay on the sand but then you can just go inside and pick it up.

I was able to get 4000 (in game money) for selling a full inventory of sugar cane.