It's 1 materia per piece of equipment. Probably at 100% chance to meld.

So, no, it won't drain everyone's money, unless they hope to NEVER earn any gil in any way whatsoever besides running dungeons and hoping the 69 gil drops pay for their food, potions and materia. They could farm fleece or any of the good leather skins and make largely more than enough.

I'm a sub-leader in a 67 player FC with 3 airship and a massive 348k credits. I'm the highest crafter in the FC, probably the wealthiest (bar isn't so high, but I'm not poor). And I think it would cost less than 2 million per 2 patch (for 3.2, but not 3.3), if we do get V tier more affordable/accessible. You could get 100k from 200 cobalt ores half the time (price fluctuates between 250 and 450 each ore), in what, 20 minutes of gathering? So, in 6-8 months this represents 6 hours of gathering. Other money making methods exist, I just don't know how fast it is to the minute. It's still reasonable for most.