A 424 is a kit from Warn (no longer in production) that replaces your front drive shaft with a split shaft & gearbox- you mount a "selector ****" on your fender that allows you to disengage the 4x4 and spin only the rear live axle. This redirects 100% of the hp to the rear axle and frees up your front end for better handling in tight trails. I have one on my 99 TRX300fw. They are not easy to find, and are no longer in production by Warn.
Also- I don't know where reconranger is finding any decent 2004 4x4 atv's for only $1k- but in any case, you paid an appropriate price- I've seen '94 basket cases for less, and mint ones for more. Any decent shape 4x4 atv is worth $1k!
I would fix that electric start tho- no fun trying to kick over a stalled atv in a deep puddle or on a steep hill!
I posted the service manual at this link:
it might help you discover the issue with your starter-