Valkyrie wrote:What Horst said. The Paladin/Errant kit is the most basic one, you only get the RFBC, Melta and Reaper.
The benefit here is that it's the least valuable kit, so you can buy a complete one on ebay for like $90, new on sprue. So if you buy a Canis Rex kit and a Paladin kit from ebay, you can build a Gallant and a Crusader, which is a really good combination of Knights to field.