Is it permissible to register on websites that display skills and capabilities as "featured" for a fee to top the search results, while free registration places one at the end of the list?

There is no objection to the website displaying the CVs of job seekers and mediating between them and employers, whether for free or for a known fee. This is because it falls under the category of permissible brokerage, provided that the mediation is for a permissible job. There is also no objection to the premium registration, where the CV owner pays a fee to have their CV displayed at the top of the list.