Baseball cards are one of the roughest investments...the late 80's and 90's killed the market with extreme overproduction. Anything I have pre-1985ish is still low, but I can cash them in at a high return on original cost. Anything later, I'm lucky to break even.

I have a ton of tribal art/artifacts from Mexico, Papua New Guinea, and Irian Jaya. Considering that I bought all of it firsthand from the producers of it, I can easily sell it for tons more than original cost...but I would then have to factor in the travel expenses and personal memories involved with the items, so it would be hard for me to part with them.

I also have a very modest coin collection, both US and from other countries I've been to...actual value is about 1.5x's of what I originally put out. Now isn't a good time to invest in silver because the price of silver is so high.