Sending out your retainers like FFXIV crazy will net profit

Sending out your retainers like crazy will net profit. I have a miner retainer and she gets about 5k-15k per hour. Doesn't sound like much but considering all you have to do is press a button then check up on them later its a lot. I also have a battle retainer who will occasionally get some expensive items.

I don't craft to sell and the amount of gil I have is Buy FFXIV Gil in the millions from just saving up and selling things.

If you got friends to help, a 4 man unsync'd Ramuh EX can get you Large Levin Orbs. 1-1.5million on my server. Split amongst friends is 250k+. Drop rate though could be an issue, its pretty low.

Just meld Grade IVs unless you're progressing through Savage. You'll be missing +6 Det, +3 Crit, or +8 Str, which is a stat weight miss of 1.626, 0.918, or 8, respectfully. Taken over all slots, you'll be missing at worst ~67.5 stat weight which is equivalent to almost 1 accessory.

What does that mean practically though? You'll do maybe like 50 dps less than you would have? So unless you're progressing through Savage, 50 dps doesn't matter so why spend a ton of gil over nothing.

Don't buy on or near reset day (tuesday). This is because a whole bunch of ppl would've gotten either their Midas drops, Lore purchases or Weeping City upgrades and thus will be needing Tier 5s. In my experience, Friday midday is when its cheapest.

From everything you've said, you appear to have a lot to learn about the game, including:
How markets work: supply, demand, and their effect on prices. Rare and valuable items will never be priced at a point where everyone can afford them. Same as in the real world, you have to really put in work/effort to afford them.

The actual effect of stat numbers - you seem to think Grade V is 'the best' and so you must have it. But at your current level, and really all the way up until the top levels, grade IV is a very minor difference and more than enough for your needs. Honestly with available gear even A8S doesn't require Grade V materia, and I highly doubt you're anywhere near there at this point.

What stats do - again, you seem to be going Cheap FFXIV Gil for 'the best' without knowing what that actually means. Yes, strength materia is best for tank accessories, but you need to understand why before you can make good choices, otherwise you'll just end up spending tons of money and still getting laughed at for noob choices.

What you have to understand is that equipment for raiding is very much like many real world sporting activities. Let's take cycling. Yes, if I want to get into competitive cycling, I probably have to buy a very expensive bike with expensive modifications, upgrades and accessories etc, because those are 'the best'. But if someone is just getting into cycling and spends all their money on 'the best' equipment and complains about it being too expensive for entry, they'd just get laughed at because they're just not even in the right position to complain.

Bottom line is, yes high level raiding has some decently high barriers to entry including gil expense, but this is to be expected and is not a bad thing.

P.S. Also most importantly. You have to recognize that there are many facets to the game which you do not yet fully understand. So don't lash out defensively at people who are trying to teach you, and don't act as if you already know everything. Keep an open mind :D