eBay
Educational Insights - Wireless Eggspert 2.4g (EI-7881)

This is the system with the blue base.  Comes with 6 buzzers, [the green buzzer does not work for some reason though] controller, and light base.  Missing instructions.  Box has slight wear/tear and scuffs, but otherwise fine.   Remote requires (4) AAA batteries, system (4) AA batteries, and each buzzer (2) AAA batteries.  No batteries included.  Has AC adapter jack available.  No AC adapter included.  Great value!

Email for questions.  We are fair, honest, and easy to work with.  Ships to US residents in standard bubble mailer envelope.