Hi. You don't need to spend $100 on a cleaning kit. The assorted jags and brushes should all have the same thread(or there are adapters) so you can just buy a basic kit and the brushes you need. Never heard of any course, but it sounds like you have the cleaning part down anyway.
This one will do the exactly the same thing as the $100 kit. It just doesn't have a fancy bag.
https://www.cabelas.ca/product/4288/...l-cleaning-kit
Is the Beretta a 12 gauge? You'll need 12 gauge patches and a brush. You'll need .22 stuff for the others. Keep in mind that .22's don't need constant cleaning. Only if they get wet(WD-40 is your friend) or once a year. As daft as that sounds.
You absolutely do not need more tools that as a mechanic you already have. The hex wrenches you use on stuff like head lights will do nicely. So will any screw driver. Although you don't need to disassemble any firearm to clean it. Or for any other reason than just wanting to. Some of us are like that.
You can save a pile of money on patches by buying a couple yards of remnant flannelette(winter PJ/sheet cloth. Ask the women in the store.) in a discount fabric shop and cutting it into suitable size patches.
And anything that has the word "gunsmith's" in its name will cost more. Just like stuff with the word "mechanic's" in its name does.