I'm level 67 atm, and finding myself spending about 200k/level on ammo.. orz.
What the hell are you shooting (Steel +2?), and why do your DDs suck so badly that you're going through that much ammo? You shouldn't have to spend THAT much shooting, unless you are the main source of damage for your party and you're non-stop spamming Steel Bullets as fast as possible while the rest of the DDs aren't pulling their weight. On that kind of party, constant COR/RNG shooting is likely to make you the main tank too :P.
You need 27,500 experience points to get from level 66 to 67. Let's say a stack of Steel Bullet pouches is 200k, which looks pretty close to cross-server average on ffxiah. 27,500exp/12 = 2291 exp per bullet pouch if you're using a a 200k stack per level. Are you seriously going through an entire stack of Steel Bullets for every roughly 2k experience points? If that's true, you have much bigger issues with the quality of your parties than you do with the cost of ammo.
Also, many very popular TOAU Level Sync camps aren't even of a level where you can use Steel (66+). Well, you COULD still shoot them if you can equip them with synced down stats, but that would be a really bad idea. So that's quite a bit of ammo savings right there. It's pretty easy to re-cap marksmanship skill if you sync down, just spend some time in Besieged with cheap NQ bullets.
Another recommendation that saved me a little gil in the 60s-70s without a multihit melee weapon - try some pulling. A COR/NIN puller can (and should) still be firing plenty of shots during fights, but leaving early for the next pull and re-applying Utsusemi and rolls during the fight takes up some time so you aren't able to be constantly shooting like you would if you were on COR/RNG as a DD+buffer. I like COR/RNG a lot and it's my preferred way to play COR, but I mixed it up with COR/NIN and pulled a decent amount in 55+ parties as well. I viewed it as both an opportunity to improve my skills as a COR puller as well as a somewhat cheaper couple of hours getting exp.
Also, I really don't think it's "gimp" to use Iron instead of Steel if you're shooting for TP in a regular exp party and you're having a hard time with ammo costs. Completely understandable given the cost and availablity of Steel. Just make sure you're using Steel for WS/QD.
level 70 - level 54 = 16 levels
16 levels * 200k = 3.2 mil
Average price of a Mercurial Kris = 3.4 mil
Don't forget that you're still shooting your highest quality available bullets more often on WS with a M.Kris. Yes, it isn't as many as you would use shooting for TP, but you will WS a whole lot more so you still have to buy a significant amount of ammo. A real comparison in costs would require you to include the price of a M.Kris PLUS the price of ammo you use for WS from 54-70.
Plus, as discussed above, I think that 200k per level is way too high even in the upper 60s using Steel, much less from level 54-70 where the majority of the time Iron is your best option (54-65).
Though it's certainly true that M.Kris can be re-sold, and that's the big draw. If you have the gil, go for it. If not... I'm not sure it's worth farming the gil to buy and refusing to level without one. Edited, Mar 30th 2009 4:24pm by Anza