Way too damn much money. Going rate for the superior 03/04 unit is $1000. The 01 unit is a better than the 99 as well but not as good as the 03/04 and that can do $800-$900. $700-$800 is ballpark for a 99 IRS.
Only way that 99 IRS is maybe worth that money is if its insane and I mean INSANE low miles.