This gets overstated all the time on this board. Ginobili was a free agent twice, with this off-season being the second time. The first time, there was a rumored offer from Denver which was six years, $8-9 Million a year. Ginobili ended up signing for six years starting at about $6 Million. Why he signed for six years, I have no idea. Even if he were all about sacrifice, he didn't have to sign for that long. But I think he did because that was best offer that was actually extended to him. But whatever.
After he was almost done with that contract, he signed for a max extension in lieu of going to free agency. Before people laud him for that sacrifice, remember he had just come off one of his worse seasons, and there were serious thoughts that the team was going to trade him away or at least let him walk. Washington offered the fifth-overall pick and Arenas for him, which the Spurs thankfully rejected. Then Ginobili blows up and signed his extension, which gave him the security he needed in case he had a bad finish to the year.
Manu could have tried to wait until free agency to try for a max offer. During his prime, he probably could have gotten one. But he also signed hefty deals with the Spurs to forgo that. He's never done anything like Duncan and purposefully took less so that the team could stay together (at least from what's been confirmed). If anything, he was like Parker in that he signed long-term deals at the wrong times. That doesn't make him a money-grubbing selfish player now. But it also didn't make him a saint then.