Be careful with LinkedIn offers. Many can be scams. Just don't put any $ upfront and if a job is too good to be true, it probably is. Make sure to research the name of the recruiter and make sure the phone number to call back belongs to that person. In times like these, there are a lot of predators out there looking to take advantage of people who are desperate for jobs.
I've received a lot of requests to connect, but I refused them because I do not know these people. It may be they are looking to create a fake network of credible professionals. Then rope in susceptible job seekers. Some may be legit but just be careful anyways.