Now that we know we're definitely keeping our rental car, a convertible

, I've been checking other sites besides Alamo.com for rates. Seems like I've scored big time by renting thru alamo!! The base charge for the time that we need it is $164.99 whereas on avis.com, the convertibles will be over $400 and at hertz.com it's $289!! So, I guess I did get a great rate after all!
But it makes me wonder, if one company can charge so little, why can't the others??