Nathan,
I'm a book collector with about 22,000 volumes in the house, and various storage places. (Very little JW stuff, though.)
I can get Russell's Studies for you on ebay at pure cost, no profit, if you want someone to shop for you. I shop there a lot anyway. Been looking for two items that I would like for myself. I don't care about Rutherford's books but I can look for anything you are specifically looking for. (Some of Rutherford's are more expensive than Russell's.)
I can usually pick up Russell's studies Vol 1, 2, 3 for less than $10 each on ebay, but 4, 5, 6, & 7 go for $50 to $100 or more. Of course, they all go for more if they are early editions or rare editions, but if you just want have one for reading any edition will do. (Just saw Rutherford's Comfort for the Jews go for $142 and then another for $178 in the last two weeks.)
For myself, for a personal project, I'm very interested in
1. Studies Vol 3, Thy Kingdom Come before 1904 (I'll trade a 1907 in great shape + cash).
2. Also I'm looking for a Vol 4, Day of Vengeance (also called Battle of Armageddon) from anytime before 1916.
3. Also, I'd like a Studies Vol 1, Divine Plan of the Ages from around 1927, (I'll trade a more valuable early edition for it.)
I just found out that most of my research could be done on full copies of the text of all volumes 1-6, and anything else Russell ever wrote, using Bible Student sites, but I still need the 3 I listed above for the variant readings.
Gamaliel