Is one who prepares a fictitious price offer to help his friend sign a contracting agreement, at the request of the official in charge of the project, committing a sin?

Submitting fictitious price quotes is a form of lying, because it is informing about something contrary to the truth. The Permanent Committee has issued a fatwa (definition) that this is considered forgery and lying. Often, the intent behind these quotes is deception and fraud, which further intensifies their prohibition. Therefore, it is not permissible to submit fictitious quotes, because it is a forbidden lie, and if it leads to deception or fraud, the submitter is a partner in the sin.