I fixed up you up to make your reference a clickable hyperlink.
The $34.99 one looks very much like they went to Wal-Mart like I did, bought the $9.94 compressor, shucked the case for you and wrapped in some funky white shrink wrap to hold some of the loose cabling (a good idea), threw in a $2.99 repair kit from a another row, a $2 air pressure gauge, and a $1 bag from another department.
So, I'd estimate it's between $15 and $20 worth of parts from Wal-mart. If your time hunting down the pieces and shipping exceeds the difference--then I think you've got the arrangement that many an LD rider has stuffed in their bike.