I agree with Santiago in the LinkedIn reaction. If your company or you post a job offer, you will be crowded with offers of professional services and recruiting services from around the world.

Even though this post is old, I think I can add some valuable information for future reference explaining some of the most common conditions for that kind of service.

Usually, they offer candidates in 2 to 5 days, and, commonly, they send you a report on those candidates with their analysis. Some companies even make a technical test to fulfil the hard skills of their report.

From my experience, the price mean is around 15% of one year's brute salary of the candidate, including bonuses. However, they have different prices depending on the number of positions to cover, your relationship with big players who can refer you, or their necessity to join new markets or sectors.

You can activate other elements in your negotiation, such as exclusivity during a timeframe, which usually is between 2 and 4 weeks.