Another way to earn Clue Scrolls (and perhaps the fastest) is to buy Implings, which were previously taken from RS gold a jar. In the event of opening these containers, it could result in a Clue Scroll reward. So if you want to gain quick access to the Treasure Trail of your choice opt for this option. However, this method can be quite expensive. It will cost lots of money if want to get quality difficulty scrolls that aren't found in Jars.
Even though clues from this tier have the lowest requirements yet, there are a couple of drops, that can be very valuable. In the first place, you are able to choose a prize from the drop table that is unique at the rate of 1/24 for each drop you collect. In other words, if you collect three drops, it leaves you with a 1/8 chance of receiving a unique.
Of course, if you are fortunate, you could get even three of them inside one casket. The value of items on this table ranges from 10k to 100k, but there are some exceptional items like the Rune Scimitar Ornament Kit (Zamorak), which can be sold for up 500k gold on the Grand Exchange. In addition to buy OSRS gold unique drops, there's nothing to be noted within these caskets.