You're probably looking at the prices for the four-week courses? PostgreSQL is a six-week course.
Sweet. I'll offer 20:1 that the final price falls between $100 and $4000.
Can anyone do better?
I am not going to bother responding any further either way, but hopefully you just answer the question with a number, approximate, guess, average, median, I don't care. Maybe other readers will find it useful, I am done.