Generally, if you buy the whole item before B-Grade you will be wasting loads of money - the key is knowing within crafting what to buy and what to manor yourself.
As a blade dancer, you're looking at three investment groups: Blue Wolf Heavy, Tsu*SLS and Black Ore Jewellery.
Among these, you should buy from store the Tsu*SLS and overenchant them using a blessed enchant B to access the SA, and craft the BW as well as the BO.
Key mats and recipes for BO are a dime a dozen, so look around Giran a bit and you should be able to find some cheap. The BW materials are a bit tougher - if you don't have a clan to help with them, be prepared to run around in the areas where they drop (check stratics (
http://lineage2.stratics.com) for a detailed drop guide) and pester both people and farmers. :)
The biggest investments in the ring are a whole bunch of animal bones, which you can and should manor using Chilly Cobols (they still work decently at 54, so it should be no problem even if you're above the level) - provided you can manage. The other materials aren't as pricey, but you might want to look into manoring the varnish. The rest can pretty much be bought in the market.
Blue wolf armour once again contains massive amounts of animal bones - chilly cobol, chilly cobol, chilly cobol! You'll also need more golden cobol for this, as well as a way to get some iron ore - the seed for that is fairly unreliable though,s o you might have to do it at a higher level in Cruma Tower or something like that, if Iron Ore is up in price.
There's also much more animal skin than you can ever hope to get in drops (especially while manoring :p ), but that's what the market is for - try to buy it, and remember to check for ready done leather, which is sometimes cheaper than the skins themselves.
You might also want to join (or make) some rift parties in the level 50 rift to try to get to the raid boss in there - the setup should contain at least a proper tank, two healers (having an SE and a bishop is ideal, although having a WC and a bishop would probably work), and the rest proper DDs.
I hope that helped a little. If you're just getting into your C Grade, practice crafting parts of that so you don't get dunked into the cold water when the B Grade rolls around.
And if you can't make the manor yourself - find a trustworthy friend who can. :) I'm currently holding about 1.5million adena worth of mats for Zeine of Devianne that I handed in for him. :)