You want a civilized discussion? I'll bite.
Someone mentioned "don't say these things are easy - just because they're easy for you, doesn't mean they're easy for others". Let's play this argument - let's assume the common player doesn't have 20m gil available at all, a fair assumption. From the complaints I've seen, the average player seems to have anywhere from 100k to 2m. A lot of players like to be snark about how 18m is actually pocket change (since, depending on the point of view, it is) but they don't explain why. So let me try to elaborate.
I don't think RMT matters in this situation, especially not in the servers you mentioned. The amount of gil wealthy players have is really, really high. There are way more super wealthy players than you think. These are not necessarily crafters, they can be:
Combat Spiritbonders
DoH/DoL Spiritbonders
Primal/Coil run sellers
Gatherers
Market players
Estate resellers
Some of these are nasty activities depending on whom you ask, but all of these people exist, and they have huge amounts of Gil. The average player who's actively playing the game with a financial mindset should have at least 10m, usually 30m-50m. More seasoned players have 100m+. Almost all of the 1.0 veterans I've seen who play the market have at least 100m-200m. And then there are the whales with 500m,1b,2b,4b+.
What do all of these players have in common? RMT is irrelevant to them. The people buying these glamours have an insane amount of Gil. 18m is pretty much pocket change to these players. I can't stress this enough - the order of magnitude of Gil some players have is enormous.
So let's take a look at what's happening right now. What is happening is that all of these people who accumulated mountains of gil finally have a reason to spend their gil. And as a consequence the people who can provide any service is having a rain of gil poured over them. I don't think Square/anyone saw these prices coming (much less planned it), since these items arent particularly rare - this price is entirely based on the mid-tier crafters being aware of the whales holding tons of gil. They may seen rare now but this is gonna change eventually - as others have pointed out, this bubble won't last.
I do want to point out one thing, the issue with crafting at the moment. People like to say that glamour is the true endgame, and while they say it as a joke, it is nevertheless true in the economical sense. The insane price of glamour in general is a consequence of the high entry cost of crafting and the fact crafting is for all intents and purposes useless for gearing for combat. You're stuck selling cosmetic items and gear for crafters. House furnishing sells slow and even things that sell for millions arent really profitable due to the liquidity risk, which is very high. Every glamour item is eventually going to be subject to that - even the Thavnairian Bustier.
Let me say I do understand your position, though. The entry cost to being able to make gil in this game tends to be high, and if you're not used to it you're bound to miss opportunities that are transparent to seasoned players. This is extremely frustrating and disencouraging. Lastly, I am not gonna lie - I find the price of these items a little awkward. With that said, it is not bad that there are some crazy expensive cosmetic stuff, otherwise all that gil I pointed out wont come down. It is most unfortunate that sometimes this is stuff that's of interest to you, but do try to take advantage of the situations and see how they are profitable, be calm (since the items ARE gonna crash eventually!) and sooner than later you'll find yourself having all the toys you wanted.
I do hope my point of view offered you some new perspective on the issue at hand. Hopefully you'll have your Thavnairian Bustier!