There is more than one issue here but, the original question was what to charge. There is a big difference between teaching something that can be completed in one day vs 2 weeks. Carving an oak leaf can be done several times in one day and only requires very minimal tools and is realistic for dedicated full time teaching and oversight. Making other or larger projects that require multitude of tools and might take days or weeks to complete one is a different story. The more complex a project the more a student needs to practice steps/tools over and over therefore; direct dedicated instruction is not realistic. Dedicated time should receive full hourly charge plus significant premium depending on quality of teaching (not necessarily on teacher's ability/mastery to do the work themselves). In other words there are master makers, master teachers, and occasionaly both. To really learn from a master maker, you need to be pretty skilled to begin with or you can not even appreciate or translate the touch of master to your work. doesn't matter if the object is a fully tooled oak leaf or a strong, perfectly fitted tree or saddle. You have to be pretty knowlegable & skilled to fully gain from a master maker.
I would think that tree making or saddle making is comprised of multiple skills. Some of these skills can/should be learned outside a dedicated instructional saddle/tree making enviornment. In other words you should not be teaching how to use a band saw or a sewing awl in a $100/hour class. But, I would think a $100/hr would be the absolute minimum for fitting, assembly, and finishing skill teaching. That rate would go up if you have a planned course and proven path to teach a student to be competent (not a master).
STORY: About 20 years ago I was in an advanced goldsmith class. Anyone (limited to 3) with $900 could attend the 3 day intensive workshop. One of the students spent most of the time learning how to adjust his torch and handle a Foredom handpeice. Do you think that person left with any advanced skill???
I hope those of you living in areas with guilds and other leather workers fully appreciate that value.
Regis