Soloban is expensive, no doubt. It is worth it if all you have to do is tie it on the bimini and plug it into a charge controller.
If you build mounts and a hard bimini it would get expensive quick. Stainless steel parts are expensive in and of themselves.
I use 100 Watts because I run an autopilot, VHF with AIS, GPS networked into the VHF, stereo, depth, and I do things like charge my laptop, camera, and other items. I use lights at night. The thing is that I never worry about power on the boat. Most of the time the solar panel is running everything and the batteries are staying charged up to the max. At night they get some use (I also run a 12V fan at night when it is warmer and sometimes run that a lot during the day).
You also have to consider weight on the Compac 23. The weight from adding a rigid panel and the mounts could weigh the stern down some and make it squat.