The going rate for a swimwear model for a catalogue is usually about $150/hr. That said, your model's rate will vary based on lots of factors: her experience, where you are located (what city), how long the shoot will take (a full day can get you a discount, some models have a two-hour minimum), whether you are booking her through an agency (more expensive, more restrictions) or direct (you can negotiate a flat fee or other non-cash compensation), and most of all, the usage. If its for a national consumer cataloge, expect to pay more. If its for a national beer billboard campaign, expect to pay a lot more. If its just for your book, it could be no charge if all she wants are prints. If she wants money, you have to decide how much she is worth to you.
Andy Pearlman Studio