i coulWhats the lowest price d get for a 240-300 swingarm kit (6-8 inches)?

Question

I jus dont understand why these things cost over 5 grand?

Answer 1

Because fitting is a pain and its low volume production. $5,000 plus is too expensive just for kit but probably about right for kit and fitting. (paint extra)
Swing arm is going to cost around $700.00 to have made.
Wheel depending on exact size and type will be from $400 to $15,000.
then you have all the ancillary components like brakes, tyre is a good idea, offset primary, strip transmission to fit longer output shaft.(if its a Harley)
Hell, starting to sound like $5,000 is a bargain