My business rate is set at a level that replaces lost income from my broadcast engineering projects. The first half day of preparation time is not charged.
Travel expenses pass through with no mark up.
I will trust you to treat me as you would treat any guest speaker, etc. On consulting projects, there is no charge for up to 3 copies of any report prepared as a result. Alternately, I will send you electronic copies of the materials and you may have them printed and collated. Also, if your group is more than a few people, a computer projector is used for seminars and workshops. If you have one of these in-house, I will use yours.