What do you think is the best long term investment (maybe 20 years) for any given player? A) Rookie Card B) Autograph Card C) Jersey Card D) Error card E) Sticker F) Special Insert Card E) Gem Mint 10 Graded Cards (or 11) Nobody can collect everything. What are you focusing on?
I quit collecting about the time that "graded" cards became the thing...the only thing people wanted were graded cards. Before that, my philosophy was to try to get the upper end rookie cards of my favorite players and the new "potential" guys as well. I wasn't hunting for the insert rookies, just the regular rookie cards of the upper end sets. I would also try to pick a nice, middle of the road set to focus on and get a box or two of that. I'd pick a different one for each sport I collected each year. Then I'd always buy a couple of the upper end packs just for a lotto chance of getting a good insert. Thats about it...I was always more of a Starting Lineup dork anyways.
I'd say rookie cards - real rookie cards by bowman chrome or a super premium brand. Inserts, autos, gu, etc are all rarer but it's supply and demand that drives a true price up and everyone wants the rookie card. Now if you want to take all the guess work out of it and you have deep pockets - a gem mint, gu, #d, auto rookie would cover most bases.
For pure value, rookie cards and autograph cards (or both together) are the way to go. (You can always get the card graded later.) I personally don't like relic cards. They don't hold in value, and everybody has 'em. I tend to stick to autographs (especially sequentially numbered or dual auto ones). Base card autographs are also worthy, IMO (i.e. they're numbered and part of the base set). Any autograph that's rare will be worth money, no matter who the player is. If you have a choice between Sammy Sosa, who, let's say, has 2000 autos of a certain card on the market, and Scott Rolen, who only signed 50 of a certain card, I'd go with the Rolen one. Scarcity is key, and collectors DO figure out what's scarce and what's abundant. Short printed rookies (and rare parallel cards) are also valuable. Check out Beckett.com, ebay, or thepit.com for detailed individual card values.
I've been on e-bay a lot lately and have been buying the autograph cards at about 60% list value. I noticed the value doesn't increase a whole lot tho. So I wonder.