>Implying that a single emerald is worth ~$20 trillion.

@Ichijoe  
i guess it makes sense considering how RARE is it is for rarity to actually MAKE a dress…those things must be so expensive she only makes like 12 a year,one for each month…cause yaknow,she needs those money baths and all…

>implying green gem is worth more  
dragons are the 1%

I thought that Gems grew in Equestria like Weeds. Ya just need a Unicorn Pony (i.e. Rarity to locate them), for ya.
 
*See Ep S01E19 - A Dog and Pony Show

@FloydPinkerton yep. That’s our job.

I don’t think the writers care much about how the stuff in this universe works. They’re just concerned with telling stories and making jokes.

It was self built.

I swear the writers are just phoning it in sometimes.They can’t seem to make up their minds whether gemstones are absolutely priceless in Equestria or common as gravel.

@Background Pony  
Another option might be that most of the larger ones we see are the equivalent of manufactured diamonds today, they’re either produced or enlarged via magic (perhaps not even intentional in many cases, just ambient) and are considered lower grade as a result. True gemstones produced by natural geologic forces would be much harder to get and would be consider far more valuable by contrast.
 
If you’re interested in really over thinking it anyway.

Dragons, they are rich.

The dryer must have been made by a bankrupt company. And the CMC might have bought it at a huge bargain from a liquidation store.

Gemstone value depends on type, cut, color, clarity. Rarity’s teeny ruby could’ve been more valuable than Fluttershy’s sizeable quartz.
 
Source: I heard a commercial on the radio one time.

Was probably just a rental, they had to have it back by five.

Dragons livin’ the rich life.

That or the hair drier was on sale? I dunno, the value of gems seems wonky in this world…

Dragons in general eat massive amounts of things that are apparently worth money.
 
Makes you wonder what Rarity’s doing with that tiny shop, her dresses must cost a fortune and she’s always selling them.