Chronological format is most commonly used. It is best format for recent graduates and fresher applicants. The details in such CV are presented in the bullet-ed points and are categorized into different sections. The skills are generally listed after the career objective and before professional experience details as fresher applicant will not have any eye catching experience details to grab the attention of the employer.
The cost is too good to be true. It is only human to try to find the best service at an affordable price. However it is also true that you get what you pay for. If a service says that it can write your resume for a few dollars it is better to be cautious. Creating good quality resumes requires using specific skills. The cost can be lower only if the summary of your career is part of a mass produced set of similar documents.
There used to be a day when you could create one generic resume and then blast it to a wide range of jobs you were interested in applying to. Even if you are using a resume service this practice of blasting is generally frowned upon. HR professionals are inundated with resumes and they want to see that applicants have read the ad and are responding directly to it. One-for-all type of resumes are easily spotted and are generally discounted by HR. So work with a resume service to see how you can best tailor yours for each job you are applying to.
When people apply for positions and send PDFs the employer or recruiter has to open each email download the resume and view it. Since there are many unemployed and underemployed people job hunting there are many job applicants applying for positions and because of the time it takes to view each PDF many applicant resumes may never get seen. When job applicants send a direct link to a resume page its much quicker to view a job applicants resume. If an employer or recruiter likes the resume page they can down the resume right from the resume website site and also view the job applicants complete online profile.
No sample resumes are accessible. A competent resume writing service will provide a number of samples for review. You can assess the quality of their work only if have these samples. If there are no samples available on their website ask them for the specimens of their work. If they are unable to provide satisfactory examples of their work you had better opt for another service.