Looking at the camping world website, they have 18w 'system' for $103 without installation or 50W panel for $300 without anything else or installation. i'm guessing you are looking at no more than 50W from the Camping world deal.
There is no way it would charge 220A batteries from 50% in 4 hours under anything less than optimal conditions (maybe from 80%). In my year with solar panels, I have never had optimal conditions. In January, in the Everglades, we only got a total of about 4 hours of good sunlight; with 400W we could replace what we used. With 50W we would have to pull out the generator.
What they are trying to sell you is a solar battery maintenance system for when in storage. You are better off with the generator if you plan on dry camping.