Probably those sapphire, emerald, ruby type things, they feel like they must be really expensive as well and I think they pass as comodity. Not sure if they are really commodity or if they are expensive for that scale but it feels like it.

Oil is a "comoddity" if you count that, it is not really that expensive if you take a litre of it but if you consider the sales of that happens by galons that could be considered expensive as well. If we are looking at as less space as possible for as much money as possible than we can count bronze and silver and also platinum could be one of the highest ones as well and truffles are really expensive for each one as well.

There are many stuff that really worths a lot but it all depends on the size you want and what you are looking for in price. If you collect a million iphone X together it probably only covers couple dozen containers at most but it would worth insanely.