I thought it was two weeks' salary. Even in good times, two months salary is an insane figure. That's a down payment on a car, or, as Dana points out, a long vacation staying in decent hotels. Clearly my peers are going to think I'm some sort of skinflint when the time comes.
The photos are quite interesting, though I suppose it would have been an improvement to get pictures of a set of rings purchased by actual people to see if the not just the size of the rock, but the style of rings also differs depending on socioeconomic status.