Swampy,
Perhaps prices are different in different parts of the country.
TEN years ago, in Memphis, Tennesse, used in VG+ Smith Coronas were going for $650, all day long. You absolutely could not touch one for less than that. The Remington's were going for $700 plus.
As far as collectible firearms, the Smith Coronas in near excellent condition generally go for more than the other makes. Yes, I know that the quality of the Smith's were not as good as the others, but the fact that fewer were made makes them rarer, which translates into much higher prices in the world of collectors.
I have not checked prices in the past 10 years, but I would be stunned to find that they have fallen by 10 to 20%.
The 03-A3 is a big favorite at the informal military firearms matches, because of the peepsight.
Just my experience.
Mannyrock