I had no idea
You really have to find the right buyer.
Lots of $5 ebay listings go unsold.
Besides some pre- mid 1970's Hot Wheels and Matchbox, the most "appreciated" one I have is believe it or not, the Johnny Lightning "Robot" from Lost in Space.
I paid 99 cents on the discount table, and it appraises out at $5.
The best deal was a true 1969 issue Hot Wheels Charger from a swap meet.
Paid $20 worth almost $120. no package, original paint in VGC.
I remember buying a few "Snake and Mongoose" cars new as early as 1972 (when I was about four)!