Board Game Mechanics
The resource track in Power Grid leads to some interesting decisions.  If you haven't played it, the resource track has costs increasing left-to-right while the resources are replenished from right-to-left.  This has a few interesting effects:


Resources in demand tend to cost more.  
You can get resources on the cheap if you have a power plant type no one else is using.
You can hoard resources (up to a point) to make them more costly for everyone else.


Players have to make tough choices, especially since turn order is so important in Power Grid.  The player in the lead goes last when buying resources.  So a player can forego easy victory points in the short term to set up better prices for himself.  It adds another dimension to the decision-making process, and those decisions matter.