Calculated optimal Myth spending for BRDs

[Bardo]

Coil hat is a turn 2 drop which most guilds can get on farm status rather easily making the hat a rather non-optimal early purchase in my opinion.
Silly to make the allagan hat go to alts for a 6 crit increase when myth tomes are so limited.

Even considering it's a Turn2 drop and you have Turn2 on farm, there are 17 possible items from the chest in turn2.
You get 2 chest drops per week, but data so far seems to point to each chest having it's own set of items and I think it's been pretty much confirmed that you can never get a double drop.
So that's a 1 in 9 chance to get the hat each week.

So on average you'll have picked up over 2700 mythology by the time you see the allagan hat.
Not exactly odds I'd base my gear path around.

You're correct that you definitely wouldn't want to buy it first. But there are better pieces to start with anyway.
If you've already picked up a few of the the larger pieces and haven't seen the hat yet, I wouldn't continue to put it off.

*edited to correct chance of seeing hat drop*