Alright, so my past playthroughs have been glitched in terms of investing, but not with the usual suspects (Ghorza, Moth, the khajiit traders)...

Instead, two NPCs that normally do not present issues, Elrindir and Belethor, are not giving me the investment option. I'm not going to bore you with the details - all I'm hoping for is information on how to use the console (I'm on PC) to give my bugged merchants the necessary dialogue for me to invest in them.

Thanks!