At the said melee lvls the player will need the rune scimmy (40atk needed), and full adamant armour (30 def needed), an amulet of str as well as str potion could help.. You will also require the anti drag sheild RuneScape Gold, because without it, Elvarg could be able to hit up to 500 dmg.
Also, be sure to get an inventory of lobsters/swordfish. Swordfish is far superior and I was able to kill elvarg in about 40-50 fights, by using 3-5 lobbies. This set-up is for the final boss fight against elvarg , the dragon. Another thing to note, the magic of 33 can save you 10k gp (for taking a map piece and telegrabber it instead of buying it directly from the goblin)
Also keep in mind, you'll need 33 quest point in order to start this quest. (u must complete nearly all non-mem quests just to get three quest points) If you'd like to take this quest on, you can get in touch with me in games (Tarun Dragon) and I'd be more than happy to help you, and also fund you should you be low in cash. The whole quest costs around 50k to 60k. The time I completed it, the rune scimmies cost me 60k on its own thus it cost me considerably more.
Everyone has given you the best advice, apart from two things. I believe an amulet of power would be better than strengthbecause it enhances your precision and defense. A shorter sword is able to beat the dragon with a scimitar, which are weak to stab attacks.
I'd like to add this as well, but I didn't realise that he'd be required to have an additional atk at his level and yes, dragons are rlly weak to stab (was trying to come up with the possibility of a f2p stab Buy RuneScape 2007 Gold, but couldn't figure it out lol). If you decide to play with a rune sword make sure to have it set to a stab stab atk.