If you really are looking at this from an investment standpoint as well as not restricting it to pre-war, and are willing to do a bit of gambling, what about high-grade rookie cards of various players currently not in the HOF, for whatever reason(s), but who would be in there most definitely if they were just considered for their stats alone. Like Pete Rose, Mark McGwire, Roger Clemens, Bary Bonds, and the like. There is a chance, and a good one I think, that some, if not maybe all, these and similar type players do end up in the HOF some day. And if/when that/those day/days come, I can see such HOF recognition tremendously adding to their card values, especially to their rookie cards in high-grades.
Rose is out because of being banned from baseball for gambling. But with the hypocritical way in which MLB, and pretty much all major sports, seem to have changed their thinking and willingly embraced and aligned themselves with the gambling industry in recent years, I wonder if he won't eventually get in after all. Albeit, I'm guessing MLB will continue to make him pay by not allowing it to happen until after he's passed away, so he can't enjoy it and rub it into anyone's face that put him down about it before. And hopefully along with him, they'll finally let a deserving, IMO, Joe Jackson in as well.
And with all the other rule changes and ways they keep changing the game and how it is played today, I can eventually see some of the alleged (and even proven) PED users eventually being allowed into the HOF as well. Times and thinking keep changing, and it is likely that so many more MLB players were involved with PEDs as well back then, but it is just the superstar players, like those I previously mentioned, that seem to be the only ones that got the headlines and backlash for taking part in what was most likely rampant and spread across the entire sport. And then coupling that with the total farce of how MLB dealt with the admitted, collusive cheating actions and activities of the Houston Astros, and the literal non-punishment given any of the players because of that. It just seems to illustrate and present a very much more critical and biased point of view and thinking towards the PED users. The Astros' sign-stealing scheme was not a sport wide action or activity being done by any other teams or players, and was found to be 100% proven and true. But literally no repercussions or punishment at all, even in terms of damage to players reputations and how they are viewed by the media and members of the BBWAA (who vote for the inductees to the HOF) seems to have occurred. Were Jose Altuve to retire today, is there any doubt he wouldn't get serious 1st ballot HOF consideration in five years? Meanwhile, the likes of McGwire, Bonds, and Clemens were doing what likely tons of players across all the teams in the majors were doing, but they somehow seem to be singled out and their punishment amplified. It is commonly thought/felt that the likes of McGwire, Bonds, and Clemens would have easily had HOF level careers without the alleged use of PEDs. So why do they appear to be subject to different levels of punishment and treatment than those players that were suspected cheaters throwing spitballs, using corked bats, or even having team employees using cameras to steal signs from other teams during games for them? There is a certain level of hypocrisy that clearly exists, and I feel that eventually that will change and at least some of those alleged (or even proven) PED using players will eventually get elected to the HOF. And were I to guess, I've always thought McGwire would be the first to finally break through that barrier, as he is probably the most liked and media friendly of the early superstar PED users, and therefore, possibly they first one to be given the benefit of the doubt, and finally let in the HOF as a full-fledged inductee. And then I can see other alleged/proven PED users eventually getting in as well, depending on how nice and friendly they are/were to others, during and after their playing days. Here you go, and you can take the savings below $15K to maybe buy a lower condition T206 Cobb or some other iconic pre-war card.
https://www.ebay.com/itm/22494113729...256b4957044430
https://www.ebay.com/itm/31450020082...7580d49e6447cc
https://www.ebay.com/itm/26441471321...452dca5c389e75