I always use a short shifter but it is all personal preference.

The price difference is in the quality and the type of metal used. A cheap ebay one that you get for 20-40 bucks will break on you. Take it from someone who has experienced it TWICE. They WILL BREAK...consider that your warning and don't get mad if you end up on the side of the road somewhere at 2am.

As for the more expensive ones, they are made out of a virgin aluminum which is MUCH stronger than the cast crap ebay sells. Skunk2 is a good brand but my money ALWAYS is with B&M when it comes to shifters. I like the heavier all steel shifters more than the aluminum ones though.