Less than $20 for seals and a pound of grease, maybe $12, and a little time to do the work, so less than $40 to do the job. Some spray solvent and some shop rags might add a little to the cost. It's not that hard, especially with the hydraulic leveling system to raise the rig.
https://shop.redneck-trailer.com/p-2...-id-10-36.aspx
https://www.amazon.com/Timken-GR224T...a-494189488268