About a third of products do not have rounded numbers ($80.00).
Should I display decimals for them?
I am hesitant between keeping a consistent experience $143.99, $80.00, $23.12
and reducing the noise: $143.99, $80, $23.12
So you have two questions.
For the first question, yes you have to show the whole price, doesn't matter how much is the decimal part, it's part of the price, so it has to be visible.
For the second part, it a matter of opinion, at least if we are talking about numbers in text or paragraphs. Some people prefer to use .00, some people don't. Consistency says use it, readability says don't. So it's up to you.
If the numbers are in a vertical arrangement, them both answers are a categorical yes.
There isn't really a wrong or right choice here.
I would recommend keeping it consistent. You're not really reducing noise by dropping off the cents. If anything I would say you're creating noise by dropping the cents. The reason is because when I look at this list of numbers:
I'm able to easily scan it. You're allowing me to develop a pattern for quickly scanning through the information and identify the information more easily.
If you show me these numbers instead:
Now I have to stop my scanning and process why one of these numbers are different. It throws off my rhythm. Now I have to go back and re-read it again paying closer attention.
In the end it always better to have similarly formatted content whenever possible.