I used the vender to get all my fieldcraft materia 1's to make my new gear.

don't know if I was lucky or not but I got around 80 for 1mil,

at the time they were at 15k+ each on mb now though they are at 9k. (fluctuates a lot though)

plus side to doing it yourself is that you'll get raw mats from the break down, you'll also get shards and if the prices are good on your server you'll be able to sell those mats to recover your gil. and that way your raised your level and got fieldcraft / battlecraft material for free.

I would say it took around two hours to get them all so not to bad a time investment. although you'll probably hit the level cap on that ilvl gear before you get all those demimateria.