At least around here, it's very reasonable - $60 for 8 weekly lessons. Entry fees are typically 10-12 bucks per class, with a discount if you enter a large number of classses (in USDAA - AKC there are only two classes - standard and jumpers). Or you can just find an agility trial near you, and go wander around during the day and chat people up and watch the competition.
The woman that runs the show classes also runs a agility and flyball. Right up the street.