In The Garden: Help Identify this Plant: Agave or Aloe?

We always thought this was an agave, but recently in trying to sell it, a buyer disagreed and said it was an aloe. Any help would be appreciated! Thanks, Lori

 

Aloe peglerae perhaps?

 

These two sites say how to tell aloe from agave. The leaf distinction would be useful to resolve your case.
http://www.ehow.com/info_8054734_difference-between-agave-aloe-plants.html
http://homeguides.sfgate.com/difference-between-agave-aloe-plants-26133.html

 

Aloe for sure - not so sure it is peglerae. Agave's have a distinct grooved terminal spine.