Sure, Golden age keys is the right way of thinking if your looking at 10-15 years. anything else could go haywire, even keys.
The issue is that many don't have the money to buy Golden Age keys. But yeah, if you can spend it, go ahead. Here are a few to look into that aren't over 100 grand yet
Marvel Family 1 (you should buy this one ASAP)
Whiz Comics 25
Captain marvel Adventures 18
Batman 1
Detective Comics 73
Detective Comics 62
Detective Comics 66
Detective Comics 68
Detective Comics 122
Detective Comics 140
Action Comics 23
Sensation Comics 1
More Fun Comics 73
Marvel Comics 1
Marvel Mystery Comics 4