We all like to design and put in place our own plans so I thought I'd throw together a few ideas I have come up with or found on the internet.
Worm farm by using plastic boxes:
A great and cheap way to build a worm farm is to use plastic storage cubes. The good thing about these is that you can start with two. One catch tray and one first waste tray.
All that needs to be done is holes drilled in the top of the waste tray and a cover put on. The cover can just be a rubbish bag (this is mostly to stop the worms from getting over exposure).
As each rubbish tray gets more full, add another with holes drilled.
The next and very easy way to save money when planting plants is to use tyres. They are usually free to take at a lot of car yards.
If you fill them with soil, they make great planter boxes and can be arranged into nearly any shape you want. A lot of people even stack them!
Pallet gardening is another great way to save money. Instead of seed trays, planter boxes and expensive wood, you can get free pallets from your local hardware store and use them to protect and grow your plants. It doesn't just have to be veges either.
All 3 of these ideas are easy and close to free to do. While it isn't always easy to get your hands on tyres or pallets, in the long run it is definitely worth it. Good luck!