The current, consumerist habit of chucking out furniture every few years is bad news for the environment. In order to begin being more eco-friendly in your interior, the first question to ask yourself before you buy is "Do I really need it?" Do you have anything else that will suffice? For example, can an old table be restored? Can chairs be re-covered or mended?

Tips for buying
Prices for items vary enormously depending on where you are in the country and the condition of the product. Do some research before you start so you have an idea of what to expect.
Take someone with you who can give you an honest second opinion and help you check the item over.
Take a tape measure and relevant measurements from your house if necessary (for example, if you're buying a bath or sink).
If you do want an old sink or bath, you need to consider whether your bathroom/kitchen can support the weight - cast iron baths are extremely heavy!