Value has a lot to do with how desirable an item is... The Argentinian minivehicles aren't as common as their Japanese counterparts, but they aren't as high priced though.
For example, Optimus an Grimlocks aren't rare at all, but you can see they often command premium prices. In the other hand, a good shape Powerdasher is by far less common, but it will never be that sought after, just because it's ugly.
Finally, the value a figure can fetch is subject to desirability AND availability. It's logical to think the more scarce (re geography), the more expensive, but in this hobby not always everything is too logical.
