The last time the Cardinals traded for a quarterback, it cost them a cornerback, a second-round draft pick and $20.5 million. And they would be smiling today if the deal for Kevin Kolb had worked out. It didn’t, and two off-seasons later, the Cardinals again are considering trading for a quarterback. But the cost of acquiring Carson Palmer from the Raiders will be considerably less than it was to obtain Kolb. According to sources, the Cardinals will make a deal for Palmer only if it doesn’t cost them much: late-round draft picks, possibly conditional on how, or if, Palmer plays. Acquiring Palmer, 33, from the Raiders won’t be simple. The Raiders first have to consummate a trade with the Seahawks for quarterback Matt Flynn, and that requires Flynn re-working his contract. If that deal is reached, then the Raiders presumably would try to trade Palmer before releasing him. That deal is more complicated that just agreeing with another team on Palmer’s worth. Palmer is due to make $13 million in salary this season and reportedly balked when the Raiders asked him to take a pay cut. Any team trading for Palmer, including the Cardinals, will want him to take far less money, too.