Or if your area does hard rubbish collections why not drive around with a trailer and grab what you can for free?
If you don't know what hard rubbish collection is, it may be called something else where you live ^^;; It's when the council lets you put things like couches, old mattresses, scrap metal and other things too large for the regular bins on the side of the road. The council collects it and dumps it/recycles it for you. Usually people go at night with their own trailer and steal the metal to on-sell it. Sometimes people throw away pretty cool stuff though, although I've never had the time to go hunting myself lol