Breakdown of course/site costs

[Ideas]

Shmoop is unlimited (but their classes are a pain; no proctoring required; some classes require outside texts).
SL is 99/month membership + classes, but not all are $59 anymore.  They seem to all be under $100, and proctoring is included, as are needed texts.  Also, coupon codes are available.
Saylor is generally free to take a class, but you have to pay the proctoring fee for ProctorU in order to qualify for credit.  I thought that was $35, but I could be wrong.

$25 if you schedule 72 hours in advance. There are more fees if you schedule 2-72 hours in advance or less than 2 hours in advance.