My actual circumstances:
I'm just gonna save up to 1800 before spending anything.
I main a PLD but I'm thinking of switching to BLM for this expansion. If you're wondering why...well, let's just say that I do twice as much dps at iLv 166 as one of the BLMs in my FC at iLv 186. I felt that going dps myself might be the only way we're ever gonna get past some of the dps checks.
The way the game rewards tanks for trading away survivability stats for offensive stats is also making me feel less attached to tanking (been tanking for most of the past decade in MMOs).
Still, I like tanking and our FC don't have anyone who mains a tank. So I'm very much undecided. Since 180 is more than enough to do everything except Savage (and we're not doing Savage any time soon, most of the people in the FC either have statics already or are outright waiting for Echo), and my BLM needs another week or so to get full Law, I might as well save all the Esoterics.
But definitely thinking about buying the weapons. If my BLM gets to down Ravana in pugs then I might rethink it, though. Without Savage the weapons will stay at 200 and we already know 3.1 relic is going to be the top weapon for that patch. If I can reasonably farm Ravana then I might skip the 200 weapon completely.
The 200 weapon is a waste of Esoterics unless you do Savage. Everything outside of Savage is easily farmed using the 190 weapon. In that sense, people who don't do Savage probably should choose their Esoterics purchases mainly for glamour reasons.