Why is it harder to translate into a non-native language?

The final cost of translation is based on three main factors:

Urgency.
The complexity of the text to be translated.
Direction of the translation. There can be two options here: translation from Russian into a foreign language and vice versa.

It is quite reasonable to assume that translation services in a non-native language are valued at a higher price. This is a well-established practice with good reason. Consider the arguments for this increase in price.

4 arguments for higher translation costs
When working with a non-native language, a high level of expertise is required. The ideal is to have native ability in this language.
Not all professional translators choose to work with a non-native language, as most of them have difficulty achieving acceptable quality in medium to advanced texts. Some professionals simply refuse such proposals. This is especially true for highly specialized technical translations.

Finding a competent translator for a foreign language is far more difficult than for a native speaker. Only with a sound knowledge of the subject matter will a quality translation become a secure foundation. A superficial knowledge of a language is easy to spot, even with a casual eye.

Even an experienced translator will spend more time on a text to be translated into a non-native language. As a non-native speaker, a professional has to assemble the text sentence by sentence and find the right words. Automatism is of little use in this case. The translator has to consult dictionaries more often, gets more distracted and is less productive.
In the case of legal texts, the translator has to work more intently and check the pronunciation of each turn of phrase several times. Other texts of higher complexity include fiction, journalism and advertising. These texts use different extravagances, wordplay, stable and local phrases. A translator working with this type of text acts as a copywriter, editor, writer or even folklorist. A professional has to comprehend the subject and present it correctly, albeit with some deviation from the original.

If the translation contains a lot of figurative expressions, it is definitely worth using the services of an editor who is a native speaker.