Hi,
Yes, some can be quite expensive to promote. I've seen seminar costs as high as $4000 plus airfare for two and hotel.
I've had instructors teach before under the agreement that they take 100% of the door fee. At least I don't have to risk paying any money out of pocket and my students and myself receive some good training.
If you'd like to host a bjj seminar with a top rate instructor I can get you set up with Leonardo Xavier (
http://www.leonardoxavier.com). If you're interested, contact me at
seminars@defend.net and we can discuss the arrangements.
Tim