The most common and most likely answer to this crossword clue is the 3 plus 9 letter word ALL INCLUSIVE
I've seen this crossword clue in The Guardian
A
L
L
I
N
C
L
U
S
I
V
E
Buddy explains!

The straight part
We know that "with no extra charges" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case with no extra charges = all inclusive.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 ALL INCLUSIVE mean?
ALL INCLUSIVE noun- A resort that provides all amenities, benefits or perquisites in a single package.
- Providing all amenities, benefits or perquisites in a single package.