Bronze Arrows quickly rose in price because there wasnt any arrows at all on the Grand Exchange. Since no1 was selling them the demand quickly rose to 6kish. Then people tried to sell them. But no1 was going to buy 1k bronze arrows for 8M so it slowly dropped in value since no1 wanted them at that price.
Now Bronze Arrows are at 17gp.
So I doubt your going to make a huge profit on those rings.