AFAIK there is no problem with BOTW or any directory that charges a review fee. It's guaranteeing a link for money or disguising a paid link as an editorial link that Google wants to stop, and I believe they try to algorithmically detect 'sponsor' ad blocks and discount links within those parts of the site.
BOTW is one of the oldest internet directories. It's expensive, I'm not 100% sure it's worth as much as they charge, but I would be very surprised if it didn't help in some way or Google regarded it as a 'link seller'. I've used it before and I'll use it again when budget permits.