Betas can offer insight as readers, especially if they read the genres you write. Good betas should be honest, forthright, yet supportive. They shouldn't sugarcoat their critiques and should analyze the ms. from a reader's perspective. I wouldn't use a beta for "editorial" purposes.
There are a lot of opinions concerning paid editors. I think it's essential for a writer to learn how to self-edit. However, a professional editor who would give you your money's worth could be invaluable. The editor could give you professional insights that you would never in a million years realize. The editor could mentor you to become better, more objective, and more efficient in editing your own work (which CAN be very difficult to do).
If you happen to have a professional writer/editor friend who is critical but fair and would work for cookies, good for you. The bottom line is, don't settle for empty praises or baseless criticisms. Trust is the key here.