The tent with the golden swan knight seems to pretty much cover all the things needed for a jousting knight at a tournament.
That was sold for around 20-25 euros I presume? not sure since it wasnt euro's yet back then.
What if they trimmed the concept of that set down a bit? no weapon rack and less weapons, no steps to get onto the horse either and only one flag with it, not two?
Just a sword, a jousting lance and perhaps one alternative weapon which could be different in each set.
Then the price would be a little higher than the other collecting items, but not too high. Content could differ a bit in each set.. like different kind of beds, chairs and chests could be used... While all still being the same price of course.
Alternatively, they could sneak in various tournament tents into the themed sets. Like having one as described above, another perhaps with a cart that the tent can be packed on, one set could come with a training field and two knights of the same faction and maybe a maid, another tent could come with a fence and some hay for the horse as well as a stableboy to take care of the horse and a cloth for the horse's back, etc.