These would simply be suggestions, but you can feel free to pick or try any of these.
A brine sabre approximately 130k, is similar to a rune scimitar but with slightly better stats.
If you don't mind some slight defence negativities, a dragon spear is excellent as it uses all 3 styles, has some defence bonuses, it well powered, and is priced around the same as a rune scimitar, 35k.
If by "begginer", you mean around 30 attack and not confident getting hit by the monsters you train on, you might want to consider a mithril/adamant halberd.
If by beginner you ae i the 50s range for combat stats I would suggest either sticking with rune or similar equipment or going for granite and then training for dragon equip. As for a weapon anything in the sword or axe range. Cheaper may be better because of unfamiliaruty to the monsters. Brine sabres do look good but the special is practically useless.