if you can afford new get a new one.
used go for around 75 to 100, just make sure its boots are dry, the ones that cover the inner tire rods.
fluid is fluid, i used store brand fluid.
and doing this job took me 4 hrs, all by myself, zero help till i needed to get the shaft back on the rack, having someone wiggle the wheel back and fourth is a big help.
i also backed up on car ramps, then jacked the front of the car up and put the front on jack stands, im a big guy (not fat, tall, long arms dont work well under a low car lol )