The Pacers have only two bad contracts: Austin Croshere and Scot Pollard. The rest of the team is being paid in line with their ability, mostly. They only took on Pollard's contract to avoid having to pay Brad Miller much MORE, but that doesn't look so great since Scot's game vanished. Getting Artest locked up for 4 more years at a cheap price was a coup. He's making less than the Brian Cardinals and Adonal Foyles of the world. One odd thing is that they have had a pretty expensive bench. Most teams have some veteran minimum guys and second-rounders occupying spots 9-15. the Pacers have had guys like Kenny Anderson, Croshere, Bender, Anthony Johnson, etc. down there, after 6th man Al Harrington and backup G Freddie Jones. They are spending up to what is usually projected as the luxury tax limit, if there is one, so I can't complain about their budget. They will never have cap room until Pollard and Croshere come off the books, and by then Artest and/or Bender will want raises, so that might not even help.
I think the Pacers would have loved to have Mobley. One thing about getting Jackson, though, is his size at 6'8". Artest is as you know a defensive stopper and always takes the opponents best one-one-one creator. That is fairly often a SG. Jackson's size allows him to flip over and guard SFs in that instance. The 6'4" Mobley doesn't give you that luxury. The offensive creativity and ability to create space off the dribble at the SG spot is something the Pacers need. Mobley would have given them more of that, but the focus is defense and so JAckson is a good fit too. I know he's not great defensively, but he will be taking time away from Reggie, who though I have great admiration for, is no longer even adequate on D.