The regular neptune BOB.
I did just put together an avast BOB for a friend. It's a much nicer design as it has a separate plug for each ground. Where the neptune one is little screws, and all 6 have one common ground screw. It was simple to put together with basic soldering skills, and super cheap compared to what neptune gets for it.
A very easy beginner soldering project. This kit comes with all the parts you need to assemble the break out box and takes about 15 minutes to assemble. This robust terminal box allows up to six digital devices to be easily connected to the I/O port of the Neptune Apex aquarium controller...
www.avastmarine.com
$30 bucks compared to:
Advanced Monitoring & Control with the Breakout Box Seamless Integration with Apex Controllers: Designed for the Apex Controller, enabling up to six external switches for enhanced monitoring and control. Expand Your Monitoring Capabilities: Connect float switches, push buttons, leak detectors...
www.bulkreefsupply.com
$45
There is quite a few on etsy as well, with many that will custom make one for you.