I would not pay, as a matter of pride and taste. I have a strong dislike for influence peddlers.
Instead, ask your friends to review it on Apple's site. Promote it yourself. Advertise on Google and set the ads to show on the same sites you are talking about.
Well, your friends aren't getting paid, and if you explicitly declare that you want their honest opinion, and that a bad review would in no way impact their relationship with you, then there's no ethical problem.
Ethics only becomes an issue where you're paying someone to be dishonest about your product.
Instead, ask your friends to review it on Apple's site. Promote it yourself. Advertise on Google and set the ads to show on the same sites you are talking about.