Keep in mind that you'll need 33 quest points to OSRS gold even start this quest. (u have to complete nearly all the non mem quests just to get 33 quest points) If u want to do so, please message me in the game (Tarun Dragon) and I'll be more than happy to help you, and also fund you even if you're not able to pay on cash. The entire quest is priced at 50k to 60k. In the time I did it, rune scimmies where 60k by themselves therefore it cost me considerably more.
Everyone has given you the best advice, with the exception of two things. I would suggest that an amulet with power is better than strength as it improves your accuracy as well as defense. A sword of short length can defeat the scimitar of dragons which are less able to resist attack with stabs.
I wanted to mention this also, but i was unaware that he'd require the additional atk when he reached his lvl and yes dragons can be incredibly weak to stab (was trying to think of an f2p stab wep, but couldn't think of one,). If you choose to utilize a rune sword, be sure it's set to a stab atk.
Its still slower and weaker than a scimmy. But on the positive side, you could be hitting more often, as well as being less expensive. In addition, if you receive 43 prayer, you'll be able to effectively kill it without any dmg at all. But don't, u rllly aren't required to pray to eliminate elvarg.
Oh, also, when you're playing melzar's maze to find one part of the map towards crandor, it'd be best to stay away from the Demon (80plus cb) by using mage. bring along around a 100 chaos runes along with an air staff, as well as elemental runes. You can also bring 150 or so mind-runes, with an air staffs, and buy RS gold the finest elemental runes you can utilize.