I would like to point out that lucky board have a better cost than panic buy on average--it cost 20 coupon to get 1 dice which at minimal give 5 pts, it takes 7 to get a med thread, ergo it is a max of 28 coupon. However, with the chance of getting 10 pts, it's actually lower than 28, more like 25 that way. That's not to mention the free roll you could get(from free roll spot, not free dice) and the fact that the board gives stuff too, including med thread even if you consider everything else to be useless(there is completion pack too blah blah blah)
In any case, depend on how much you value the "other stuff" you get in luckyboard, I'd rate the cost of a med thread there between 10 to 24 coupon--10 if you value other stuff highly and 24 if you don't value them at all.

Second, I would like to point out that full growth value does not equal auto upgrade, what it guarantees is that the NEXT roll is going to be an upgrade. So with a growth bar of X, you might require X+1 roll to get the upgrade at maximal. So your number is low on that front by 1.
Of course, usually you end up needing less, but I guess you are not going for what is expected (and I have no idea how that can even be found out w/o knowing the code. You'd have to collect shist ton of data)

Add that to SA farming... well, I'd say ftp realistically is going to look at a tab of around 180k to get the armor maxed maybe. It's this high because panic buy is actually more or less the only way for you to get adv thread. Maybe you can get it cheaper if you save a ton of coupon and get it all at once at some 40% discount event or something...

I'm full ftp and I got rank 6 armor--because for 4 month or so I ONLY spent coupon on lucky board and went full med thread on that.
i get over 100 every month from lucky board alone, add ~dozen per week from SA and 112 a month from monthly, that's about 300 a month
Total required is only max 1400, minus rebate of 126 (You forgot the 2 to 3 rebate, thou I didn't get that personally cause mine was R3 before the first rebate event), that's only 1274(likely closer to 1k). So, perfectly possible in just 4 month.

They had med thread every month, at least in the exchange. I pay little attention to what is on the board since the exchange is a good deal in and of itself.

Thing is, my move 1 is fully medium refined, which means medium refine have serious diminishing returns. Also, med refine is cheaper, in some events you can get it for less than 20 so...

1&2 is not very interesting, but 2 to 3 does give rebates of med thread, that could be a thing(newbie might end up wasting this as 3 is soooo ez to reach, I know I did before the first rebate ever came out)

still, if you are going for worst case, you need to +1 to each, cause 50 blessing, for example, requires 51 to guarantee an upgrade.

can't find you a BA one on demand, but here is a refine one:
http://forum.naruto.oasgames.com ... 9581&extra=page%3D6
Full wish does not grant auto upgrade
Also, it doesn't matter how much it cost to go from 2 to 3, what matters is the amount of rebate given for 2 to 3, which would be on the event page or something.