I think, the review by CaiusDrewart holds really well over the years, showcasing how bad this card really is. However, there had been two cards released in the meantime, that invite me to compare them to this card, just based on the XP earned from them (not taking into consideration other facts, like that you tend to play timid and therefore bad with it): Arcane Research and In the Thick of It.
It's no surprise, that Arcane Research beats the crap out of "Charon's Obol". It gives the same 2 XP per scenario two scenarios earlier, for a much lesser price. But at least the Obol should be much better than In the Thick of It? I mean, it's a class card vs. a neutral card. Class cards have to be better? And the neutral gives you just 3 XP, the Obol so much more, right?
Wrong!
To compare these cards, you have to put into account, that XP earned early in a campaign provide you with better cards for more scenarios, than if you get them later. XP earned in the sixth scenario are double the value than XP earned in the seventh, because you net profit from them in two scenarios, rather than just one. Therefore, XP earned after the first scenario is worth 7 times as much as after the seventh, and XP from the start of the campaign even 8 times. If we take this into account, the XP*scenario value you gain from these cards are the following (assuming a standard 8 scenario campaign without any side quests):
- (Double) Arcane Research: 14+12+10+8+6+4+2=56
- In the Thick of It: 3*8=24
- Charon's Obol: 10+8+6+4+2-2=28
You have to consider, that "In the Thick of It" gives you the 3 XP for 8 scenarios. While "Charon's Obol" delays your other purchases after the first scenario by 2 XP, which would be actually worth 14. Sure, you get them back a scenario later. That's why I count them only as -2. Hence, from a strict mathematical point, the XP you gain from the Obol are only slightly more than the ones from "In the Thick of It", at a much higher risk. So go for the Obol, if you think, the game is boring without it. To raise the stake and gain some thrill out of it. But never ever buy this for the gain in XP instead of "In the Thick of It". You are much better served with the neutral card in that case!
Another option would be taking "In the Thick of It" to purchase the Obol at the start of the campaign. This is of course the highest stake, but at least it offsets the XP cost of the Obol. The XP*scenario value gained from this combo is 64 (assuming, you get to the last scenario with this investigator), the same as from "Arcane Research" plus 8 times the spare point from "In the Thick of It". This indeed looks much better. But it also increases the risk of succumbing to the Obol, starting with 2 traumata from the beginning and making being defeated in the first scenario relevant. I still think, it's bad, for the reasons mentioned by CaiusDrewart.