MINILO  I think you'll find that the complete version is $10 more, not $5. I guess some people might prefer the simpler version and are happy to save 10 bucks. For casual ebay sellers, it's easier to use as they don't need to learn (or see options for) the features that are not included, such as scheduling, messaging, store support, and some other stuff.  
(Version 1.0)

MINILO  Try Oolite.  
(Version 1.8.18)

MINILO  The reason for this is probably that the latest eBay API License agreement does not permit sniping applications.

See http://developer.ebay.com/join/licenses/individual/  
(Version 1.0b4)

MINILO  For what you are asking for (selecting a few files to view), the Finder already supports that out of the box: You just select the files you want to see in the Finder, right-click and select Slideshow from the pop-up menu.  
(Version 1.0.6)

MINILO  Sounds interesting, but there is already a Mac application called Horizon, so the choice of name is not good.  
(Version 1.0)