Well, when you consider that my options are (were) limited to the following, I think I made the right choice:
Isn't that still kind of expensive? One part of a four part season for $15?
1. Buy Part 4 used from the Amazon Marketplace for $24.99 (+$2.98 shipping) in Very Good condition, then buy the other three parts from Amazon for ~$19 -> ~$46 total for S2
2. Buy Part 4 (Special Edition) from Amazon for $33.99 and the other three parts like in (1.) -> ~$53 total for S2
3. Buy the complete second season set from Amazon for $49.49 (using Amazon credit).
4. Buy the complete second season set from Rightstuf for $37.49 (+ shipping unless I find something else worth at least $12.51 to combine with it and get free shipping).
Again, I think I did pretty well by paying ~$34 for the second season with my available credit. I also have a lot of BBY credit, so it's no biggie that I paid what I paid for 1/4 of the season.
It's also the rarest of the four sets, so...yeah.