So far, the Giants appear to be the team that has made the biggest push to acquire Marlins outfielder Giancarlo Stanton, which make a lot of sense.
There are a lot of financial reasons why acquiring Stanton would be difficult for San Francisco. If the Giants traded for Stanton, it would make it more difficult for them to avoid the luxury tax penalty again in 2018. The CBA is constructed in a way where any time a team dips under the luxury tax threshold, the penalty resets, so by getting under the threshold, the Giants would pay a 20% tax for money over the luxury tax threshold the next time they breached it, compared to the 50% they would pay in the remain over the line in 2018.
But getting Stanton would solve San Francisco's biggest problems in a dramatic way. Stanton isn't a great defender, but he's more athletic than Hunter Pence, who he likely replaces in right field. And Stanton fixes one of the most dire needs any team in baseball faces heading into 2018. San Francisco is utterly devoid of power. AT&T Park is a difficult place to hit home runs, but as home runs around the league have gone up, so have the homers the Giants have given up. What hasn’t changed is San Francisco’s home run totals.
The average MLB team hit 204 home runs in 2017. The Giants were dead last with 128, 23 home runs less than any other team. While the rest of the league's power has exploded in recent years, that power spike has skipped San Francisco.
San Francisco's power outage is especially notable in the outfield. Stanton outhomered all Giants outfielders by a significant amount.
Without Stanton or some other outside acquisition, San Francisco is power-less in a league where home runs mean more and more. Stanton outhomered the combined output of the Giants' top four power hitters in 2017.
Financially, taking on Stanton would be a huge acquisition for the Giants. But for a team with an aging core (Brandon Belt, Buster Posey, Brandon Crawford will all play next year at age 30 or older) and plenty of money already committed for 2018 and beyond, it would also fix a glaring problem immediately.