The Great Courses is having one of their better (probably best) type of periodic sales right now. This one is their "Employee Pricing Sale." This sale continues through midnight Monday (I have to assume that that's U.S. EST time).
With this sale you get an additional 50% off the
sale prices of the 80 courses that are included in this sale. I've found that these sales have the best prices of any that The Great Courses have through the year.
Audible offers some of The Great Courses courses in some of their sales. When they do, I've found their prices unbeatable. However, the courses are never very many in number, and they're frequently ones that I already have or in subjects that don't interest me.
My rule of thumb is to try to get a course (of The Great Courses or anyone else) for no more than $1 per hour of lecture time (I'm talking about the
audio courses, not the video courses). Here is an example: there is a course in this present sale with 24 lectures of 30 minutes each, making a total of 12 hours of lecture time. The sale price of the course is about $25. When you deduct 50% of that, you get $12.50. That is approximately $1 per hour of lecture time, and so I feel that it's a great deal.
I am a big believer in The Great Courses. I'm in the process of going through one of their courses now, and it is of truly outstanding quality.
All of the information that you need to get started on taking advantage of this sale is on
The Great Courses' homepage. Look in the upper left corner.