Saving Mats? Vs selling for profit
That’s far too subjective to answer. I’m a life long pack rat and hoarder of cool stuff, so I don’t sell my mats until they overflow my storage. At stacks of 2K, that hasn’t happened since the last storage expansion except for account bound ascended stuff, on which I sic my eaters.
And that means when I want to make something, I generally can. Last night one of my guilds was one celestial insignia away from Arena 2. Bam, I had the leather and the charged quartz needed and got to make a lot of people happy very quickly. Gold can’t buy that.
I did sell some mats off to make HOPE’s amalgamated gemstones but it hurts to see my empty lodestone slots …
Rule of thumb: Never keep your savings in the form of gold, as it is subject to inflation, but you do not receive any interest if you have it in your wallet.
Instead, spread it amongst items with a high turnover, mostly amongst tier 6 items (the ones with crafting requirement 400+) and alike (e.g. glob of ectoplasm), as they usually go up in price with the volume of gold in circulation.
Again: As a rule of thumb.