For what it's worth, my husband and I came 
this close to eloping.  Weddings are expensive, they are a ton of hassle (the more people, the more hassle) (not to mention the more expense), and once you invite a few it seems like you have to invite them all.  How can you invite Grandma Ida and not great-aunt Florence?  Etc.
We'd already been living together for several years, were poor, and a nice little courthouse ceremony seemed mighty tempting.
Part of why we didn't was envisioning the wrath of Onyxellian relatives.  

  That said, our wedding was a blast, all the more so for the many strange juxtapositions.