Copper is an industrial commodity...primarily used (but not limited to) the transmission of electrical current, be it wires in your home, electronic appliances, transmission cables etc. Copper pipe is also used in home water systems.
You don't buy COPPER BULLION to keep...the futures market for copper is based on industrial consumption not a fear of inflation.
If you are interested in Copper you are interested in sources of copper for industry...usually that means copper mines and businesses associated with copper mining.
The price of copper is also used as a bellwether of industrial growth. Rising copper prices mean that the available supple of the metal is in demand for industrial purposes...so when you see that the price of copper is rising it often means good times ahead industrially (or China is storing the metal for future use :) )
right now the price of copper is quite low as can be seen in this chart from Kitco Metals
http://www.kitconet.com/charts/metals/base/spot-copper-1y-Large.gif
Does that mean Copper mining stocks are a buy now??? Depends on your feelings on the industrial future in the world....if you believe that the world's problems are solved and industrialization will get a lift....perhaps it is worth looking at mining of Copper and buy stocks in that mining commodity at a low price...once the the demand for copper increases their stocks will be worth more for sure....
But if the price of copper falls further then stock in those mines will be cheaper to buy.
Whenever buying a commodity stock....always look at the value of the commodity as it will lead the price of the company associated with the commodity...can go for gold too but Gold mines are an exception since their price does not seem to follow this rule very well.
So...NO...you don't buy copper BULLION....as such....You can look at copper futures and buy contracts for delivery, or invest in mines producing copper or simply use it as an indication of the industrial health of the world.