General

Assuming:
-- you're doing this during spell trace fever
-- you have a +10% scroll success rate from traits and guild skills
-- you're buying CSS for 25m each.
-- you're buying 50% hammers for 50m each

The expected value of the cost of perfecting a weapon is going to be around 5.5b. This includes the cost of hammers, CSS, spell traces, but NOT the cost of starring the weapon.
You'd be able to get the expected cost under 4b if you manage to find CSS for 5m cheaper and you have the full +14% scroll success rate.

Alternately, if you're gonna be using safety scrolls (which are 2.8k NX each iirc), then it'll be around 80k NX, again assuming you're doing this during spell trace fever

@sokair: it's edited...

he asked how much nx it takes to perfect a weapon.. specifically how many safety scrolls... and everyone's listing meso cost of everything else

I've spent over 5b trying and I still haven't gotten it done. Somehow I feel like I've been doing this wrong..

@UrHedsOnFire: That is so wrong... Lets say you get your weapon to 10 slots, thats 50m for the weapon + 200m for 4 hammers (assuming you fail 2 pass 2) and 400m for 20 slates. Then, assuming your 15% traces have a 20%pass rate for whatever reasons like guild skill, in the 10 slots, you will pass 2, leaving you with 8 slots to css. So thats another 1.6b. And then those 8 slots, you are likely to pass another 1-2, let's say you are lucky and you still have 6 slots, thats another 1.2b. Then you pass 1, 5 slots to slate, another 1b. And so on. It costs more than just 3-4b lmao. You obviously haven't perfected a weapon before.

@Graystoke: Again, a mathematical fallacy, because the chance of slates remain the same, and with additive bonuses, the pass chances only see a mere 10% difference.

Of course spell trace fever should almost cut the cost in half... unless you're unlucky

I farmed luck days and scrolled my staff during spell trace fever and it took me about 2b mesos(though I was lucky, since I passed like 9 in a row) (49% pass chance, since 25% from fever + 10% lucky day +10% from dilli + 4% from guild). It's probably going to take you around 5b-8b to perfect. NX is useless in perfecting a weapon, all you need are clean slates and 50% hammers, which you can get in FM for under 50m each. In terms of nx, about 60-70k would be a safe bet. If you plan on buying shields and all that crap from the CS, it's gonna be waaay more. adding 15 stars takes around 1-2b for most people.

all of the above are very valid reasons why nobody likes this community anymore.

OT: it seriously depends on luck. You could hit every single 15% spell trace (and x10, that takes about 3000-4000 spell traces) in which case is super lucky and you only have to spend 20-30m (depending on the cost of traces in your market). But that's not likely at all. You are more probably to succeed only 1 or 2 out of every 10, so you probably need x150 scrolls (which takes about 45k-60k spell traces), in which case is 300-450m not even accounting for clean slates. Then, you need to buy 10% css scrolls out the wazoo. Assuming you're needing 10 for every slot, say that's 100 total, that's 3-4b right there. That's just for getting the max value out of your slots. After that you need to do enhances, but the first 11 are super easy. The next 4 are pretty hard. So, @Radiqal is actually right, ~4b is about right for perfecting a weapon using traces.

In terms of NX, 4b translates to 20k NX? So that's scrolling. Cubing is a whole nother story. You can spend anywhere between 30k nx and 500k nx to get the lines you want. IMO to speed it up splurge a little on a Unique potential scroll (2b to 3b) and then go to town with RED cubes.

in terms of nx guys - -

4bil

tree fiddy

cmon guys.....gimme an legit estimate

Zero... if you're being cost-efficient.

1... maybe 2