Oil and Gas memorabilia is a relative young collectible. Realisticly maybe 30 years old? Take a look at some older areas of antiques/collectibles their trends might lend insight to where this hobby is going.
I don't have enough diverse knowledge to make an informed analogy. However, I would say that in ALL specialty areas of collectibles the lesser condition, less desireable or common items have modest gains in value and poplularity with age. The extraordinary pieces will increase substantially over time.
Even with an aging collector base and little infusion of new collectors the best items will be highly valuable in the near and distant future. Personally I see the extremely graphic, colorful, rare items entering into the area of "art" and not advertising thus getting into "big" money or high investment ranges.
If I were looking to collect something for investment or with future value considerations, I would buy automotive signs. The car hobby is never going away (taste may change, but there will always be car buyers). Otherwise, I would and will continue to buy what I like....small independent Oklahoma oil company stuff mixed in with high quality globes and signs when they can be obtained.
