I would honestly be thrilled to get a young Paul Pierce. Dude has actually had a pretty damn solid career. He won a ring, he's made a number of All-Star games, and he's still putting up numbers after all these years. He's not a LeBron, but he's a guy that any team would love to have. I think that's a realistic and actually beneficial goal for a player. 
Carmelo on the other hand....... Having a Melo wouldn't be so bad if he wasn't such a tool. If Parker was Melo without the ego problems, he would be worth having around. Melo, for all his faults, is damn near unstoppable on offense.