The most common and most likely answer to this crossword clue is the 8 letter word TWOPENNY
I've seen this crossword clue in The Guardian
T
W
O
P
E
N
N
Y
More clues leading to the result TWOPENNY
Buddy explains!

The straight part
We know that "worth not much money" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case worth not much money = twopenny.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TWOPENNY mean?
TWOPENNY noun- A coin or stamp worth two pence.
- Ale sold for two pence per quart.
- Having a value or cost of twopence.
- Cheap; worthless; petty.