I have collected hundreds of airline "things" over the past 40 years; AA, and travel agencies. Where can I get a "true" estimate on the value?
I have things from such carriers as; Air Florida / Frontier / Braniff / TWA / Ozark / Western, etc. AA (fur shur).
Many I have NOT found on the internet.
i.e. 4 Square Ozark Cocktail glasses - 3 Employee OZ Coffee Mugs (1981 - 1983)
Name Tags, Skeds, stickers, drink stirrers, badges, pin buttons, old T-shirts.
And, a whole lot more.

I recently sold some old Airline things on eBay and was pleasantly surprised at the results.
Well worth a look.