Not exactly.
Basically, there are two factors: Supply and Demand.
Every other month or so Valve releases a new crate. Sometimes they have new stranges, but most of the time they are re-releases. Every time a re-release comes out, its previous price drops dramatically. The supply goes up, meaning there are way more of these stranges than people who would ever use them. Thus the price goes down. Some stranges haven't been released in a long time or are very rare, so they are worth more.
Another aspect of price is the demand. Both the Huo-Long Heater and the Shortstop aren't quite very sought-after weapons. Thus their price isn't much. Weapons like the Grenade Launcher (which, sadly, was just re-released) had a very inflated value because everyone wanted them.
And that, my friend, is economics.