Will we ever exploit other planets for precious metals or other non-renewable resource?
We are already finding that on our planet, resources are being scarce, and we will see oil, nickel, copper, natural gas, indium, platinum, silver and aluminium becoming scarcer in the years to come, some predicted to disappear in less than 10 years.
A good example of why this is is because the majority of our technology now a days is so advanced, it needs all these different materials, with smartphones often containing over 60 different elements.
Though, other planets may not have so much in abundance or variety of materials like that on earth, they have often an abundance of incredibly rare elements, which can help us in the future. e.g. Mars is covered with iron rich sand, reason it is red.
We will most likely also capture meteorites and other celestial bodies in the future to mine materials from, as well as setting up mines on the moon for fuel from fusion reactors to spacecraft fuel, which can be seen in the film MOON, where they mine for helium-3, a fuel needed for these 2 endeavors.
Humanity will need to leave the planet sometime in the future, and the more and more we look into the space and search it, the more and more we will feel inclined to once again reach out and travel the final frontier.
Hope this helps!