Most guilds pay anywhere from $200 - $500 for a class, more if it is a nationally known teacher. That cost is split between the attendees for a flat rate of $35-$40 and the guild eats the balance if there is not enough participation by members.
Our guild charges $40 per person and you supply your own fabrics; however, the teacher is the speaker at the meeting the night before the class, and he/she usually has kits / fabrics / patterns to sell. I did pay $60 once, but it was a 2-day class with Harriett Hargrave (heirloom machine quilting). I had to buy the batting sample pack she sells through her on-line store. I chose to stay at the hotel where the class was being held, even though it was less than 10 miles from my house, because I knew we would be going to dinner that night and didn't want to worry about driving in the dark. Breakfasts were courtesy of the hotel and lunch was provided. For me, staying at the hotel was a mini-vacation.
Most of the classes at the LQSs in my area run about $40 and you supply your own fabrics. I think $150 plus extra for the kit is a little expensive. That said, and repeating what others have said, if you really want to attend this class and the cost is not prohibitive, go for it!