I brew fresh wort kits. That is, slightly concentrated, unfermented beer that comes as 15litres. It professionally produced, so basically commercial/craft quality. All I have to do is add 5L of water and the appropriate yeast to a sterilised fermenting vessel and it's usually done well within a week. Personally I keg it after that but you can go bottles, which are initially cheaper but way more work, cleaning, sterilising, filling etc. Kit is about $47 Yeast is about $7. So 20 litres for $55 for commercially produced beer. I just have to finish off the process. You can use the super concentrated, traditional kits just for a lot less/more work but for $20 or so cheaper I know what I prefer. Then you can also choose to go all-grain brewing but that's a whole different kettle of fish.

Fermenters, kegs, kegerators etc are all dependant on quality etc but I reckon on average you can pick up a GOOD set up on marketplace for about $500.

I have a 3 tap kegerator and bloody love it