No doubt the price would go down, but Platinum has real industrial value and a lot of technologies are limited in application because of the cost of Platinum. Remember that Aluminium was once a precious metal until we figured out how to efficiently extract it and now it a common cheap and disposable thing in our lives, Imagine the economic growth if Platinum could realize a similar cost reduction.
I just looked it up...
What is platinum used for?
-jewellery
-wire and vessels for laboratory use
-thermocouple elements
-electrical contacts
-corrosion-resistant apparatus in dentistry
-platinum-cobalt alloys have magnetic properties
-coating missile nose cones, jet engine fuel nozzles
-the metal, like palladium, absorbs large volumes of hydrogen, giving it up at red heat
-in the finely divided state platinum is an excellent catalyst (such as the contact process for producing sulphuric acid). Also as a catalyst for cracking oil and as a catalyst in fuel cells and in catalytic converters for cars
-platinum anodes are extensively used in cathodic protection systems for large ships and ocean-going vessels, pipelines, steel piers
-platinum wire glows red hot when placed in the vapor of methanol - acting as a catalyst to convert the alcohol into formaldehyde. This phenomenon has been used commercially to produce cigarette lighters and hand warmers
-sealed electrodes in glass systems
-laboratory vessels, corrosion-resistant equipment
-dentistry
-currently fashionable use in antipollution devices in cars
-cis-platin, [PtCl2(NH3)2], is an effective drug for certain types of cancer such as leukaemia or testicular cancer
-platinum/osmium 90/10 alloy is used in implants such as pacemakers and replacement valves