Bob's description of why the speculator bubble burst (old comics were valuable because not many survived, as opposed to everyone stockpiling new titles they hoped would be worth money some day) is the exact same reasoning I give my friend as to why modern toys will never carry the kind of secondary market price tag as their past versions.
A mint-in-sealed-box Transformers G1 Grimlock is never going to go down in value because in the 80's no one had the foresight to predict people would still be crazy about these toys nearly 30 years later, so very few of them exist. On the other hand, whenever something is labeled "collector edition" or "limited," people snatch up as many as they can, assuring there will be a surplus down the road, effectively shooting themselves in the foot.
Another example: Power Rangers. This year is the 20th anniversary of the original "Mighty Morphin" series. Bandai released a Legacy Power Morpher, a larger version of the iconic transformation device from the old show. It's bigger, it has die-cast metal parts, and it plays the theme song when you press a button. Sweet, right?
Well, fans think so, which is why they're buying two, three, TEN of them, in hopes of turning around and selling them in another 20 years to "pay for my kid's college."
Thing is, the original Power Morphers are so sought-after because THERE'S A SET NUMBER OF THEM IN EXISTENCE. They aren't making any more, and of all the ones that were made back in the 90's, not all of them survived--they've been lost, destroyed, or just thrown out by unknowing parents. The Legacy Morpher, on the other hand, is still in production. I honestly foresee it clogging up Toys R Us' clearance aisles by the end of the year.
But yeah, you can never predict what will be worth money some day, especially when it comes to mass-produced stuff like comics and toys. I can still remember reading the old Toy Fare magazine and them talking about how valuable the first Toy Biz Lara Croft figure was going to be in a few years.
You can find it on eBay for $5 now.