I would advise focusing on the ones where you have more of a personal connection (e.g. ones you had when you were younger). There was a time when I wanted to own every Cobra from 83-87. But it got too much, so I'm just collecting vintage stuff I used to own as a child, in addition to the new stuff. Which is why I've branched out to TF, GB, etc. Sometimes I'll pick up a nice vintage piece if I can get a good price. But at the end of the day, I'm happier with the pieces where I have more of a personal connection.
Just posted that pic of your Xamot/Tomax set in a thread and it reminded me that I've been meaning to ask if I can fly out to NJ and sleep in your toy room.