Acrylic glues are just expensive, period. But they're ace glues, as they stick just about anything.
As mentioned in the Dive-in thread, alternatives include Devcon Plastic Welder, Deluxe Materials Fusion and Kevin mentioned the Uhu acrylic adhesive whose name slipped my mark one memory bank.
All of these will form bonds stronger than the material they're adhering to, and are waterproof. They do pong a bit though, until fully cured.