[Vocabulary] How to better rephrase "it costs lower by 10%"

[Ellena]

How do we say: it costs less by 10% or on 10 %? The original sentence was:
"it costs lower on 10%" = meaning that the price of the courses is 10% percent lower. Was I right when I substituted "lower" with "less"?

 

[Rover_KE]

'It costs 10% less.'

Rover

 

[Ellena]

OK, thanks)