I love these threads. It's basically members of the forums telling a newbie to go away.
There's lots of stuff to invest in. Buying new comics isn't the way to go, unless you get in on the floor with a current "hot" title. Those situations are hard to predict, but sometimes you can get word of a book selling out and then buying up some copies from somewhere else, and flipping those. But those books only hold short-term value, typically.
Other members are right in saying most stuff from the 1980's on up are not good long-term investments. The exception would be in locating super-high grade books for the 1980's, submitting them to be professionally graded, and then *hoping* it comes back what you expect. It's a gamble that would cost a lot of money over time, require a lot of experience in pre-grading, but could pay off eventually (as it has for others).
For investing in non-graded books, I'd focus on the early bronze age to silver age. Golden age books are just too spendy for most people. Most high-grade books from this period (Silver Age) are still "affordable", and will still increase in value over time, as most of the characters they feature are still relevant today. That's a key point, too: relevancy. As long as these characters are popular today, the older books will still be sought after. I take issue with so many Golden Age books in Overstreet being valued in the thousands of dollars when the book in question has very little demand on the back issue market. Personally, I've never met anyone (not talking online, here) that actively collects Golden Age books. The main reason is that most people I know have no connection to those books. Seems Overstreet deems them valuable for no other reson than they're old.
One last comment I want to address:
Lol.. comics as an investment.
Don't ever expect to find a diamond in the rough for a "steal" at any comic book convention on even swap meets.
REALLY?? Where do you live attend and conventions--because I don't ever want to live there if that's what the market is like. In my area, I CONSTANTLY find valuable books for cheap. Recently, I spent $2 on a Spectacular Spider-Man #11 35-Cent Variant, and sold it here for $150. In fact, ALL of the 35-Cent Variants I've ever owned--and then sold--were acquired from dealers who didn't know what they had. I sold a Mad Love (Harley Quinn) book for $25 I got for .33. Both copies of Avatar Illustrated Summer 1998 (first preview appearance of Goon) I have were purchased for less than $1.00 each. Last week I picked up Thunderstrike #24 (last issue) for $2.50. The last copy I had in my store sold for $15.00
I could go on, but I'm just illustrating that--at least around here--bargains are EVERYWHERE. Suppose I can thank the depressed economy...