Costs depend on the route. A port-of-entry application involves the fees collected there, while an employer petition involves the USCIS filing fees. Current amounts appear in the USCIS fee schedule, Form G-1055, and should be checked rather than quoted from memory.
The government fee is rarely the expensive part
Two structures exist and they are not interchangeable. Applying in person as a Canadian citizen means the fees collected at the port, which are modest next to the cost of a refusal after a long drive and a lost start date. An employer petition on Form I-129 carries the USCIS fees applicable at the time, with premium processing where the employer wants a fast answer.
Because the schedule is revised periodically, Form G-1055 is the only figure worth relying on. The larger spending usually sits elsewhere: an adviser's time reading the offer letter against the profession's rule, a credential evaluation if the degree was issued outside Canada, Mexico or the United States, and certified English translations for any document not already in English. Agree in writing which of these the employer will cover.