I'm a contact lens wearer since 1984, and I don't change my cases every month, either. My cases get changed if Bausch and Lomb has a special "free case" offer with products, or when I go to my eye doctor.
As for solutions, I always use ReNu by Bausch and Lomb, but I do alternate between the regular multi-purpose solutions and the deluxe versions like No Rub.