The latest craze is to grow in an old fridge.

• very cheap or for free
• very easy to clean
• well sealed
• white inside (best reflection)
• the elements in the back - even if not powered - will make everything condensate at the back, so the plants are less prone to mould
• eco friendly, since you are recycling something.

Depending on what you want to achieve, I think an old (broken) fridge can be a good solution.

All that being said, I will always suggest to grow outside, under the sun. The sun doesn't cost a thing.