Willow Short -- 120 Willow Long -- 192 Maple Short -- 240 Maple Long -- 384 Yew Short -- 480 Yew Long -- 768 Mage Short -- 960 Mage Long -- 1536
Seeing as you have only 58 fletching atm you have one of two options that would work the best. One, chop your own willows and maples (seeing as you have an impressive 83 woodcutting). Never string the willows and only string the maples if you get the string also or make the natures (as you have 63 rcing). Do that until you get to yew longs. Then if you're looking for fletching exp simply buy the yew logs and strings (logs at 275-300 per and bs about 150-180 per) and then sell them for 600 per (It's usually the easiest if you do it in groups of 1,000 or more). If you're looking for mage exp as well, then either make the nats (which I would recommend) or buy them from players in bulk at the rate of 300 per and alch the longs (reason I say make your own, is the fact that you wouldn't be losing money as you would if you bought them). Also my final thought on the matter would be to just make yew longs and sell them until you've reached so you can make mage longs and recieve a bit more of a profit by alching the mage longs. (Mage logs usually sell for 1k per, nats 300 per and bs 150-180 per, so add it up and you'd still be making a profit, although small, would add up in time)