I have no problem adding a Verlander or Hamels if it doesn't cost real prospects and you're only looking at a couple years of salary. We have money to burn the next couple years.
Holliday was not a huge signing by St Louis, 7yr/$113M at age 30, 22 WAR over the first five years (last two, he was an expensive replacement level player).
I have no problem with "value" FAs. Holiday steadily declined from his peak years, but was paid based on that expected decline, not his peak performance.
The Giants were a better team when they were prudent than recently when they started overspending. In fact, almost every FA signing and extension went bad, they won despite, not because, of their FO moves:
2010 team: the big signing Barry Zito (2006), who was a waste of money, Linecum extended early, 6yr/$98M, first two years, 8.9 WAR, next four, -2.7 WAR, they also resigned Rowand in 2007, got a total of 2.4 WAR out of his 4yr/$46M deal, Renteria, 2yr/$18m was replacement level, signed Huff for $3M, got 5.7 WAR
2012 team: Cain, resigned for 6yr/$125M, 7.6 WAR first two years, -1.0 WAR the next four, gave Huff (2011) 2yr/$20M, got -0.1 WAR
2014 team: Hudson, 2yr, $23M, 1.8 WAR, Pagan (2013) 4yr/$40M, 0.4 WAR, Peavy 3yr/$38M 2.1 WAR 1st two years, -1.9 WAR the last year
Cubs:
Fowler, 1yr/$8M [then the Cardinals gave him 5yr/$83M at age 31, 1.2 WAR this season)
Hammel, 2yr/$18M at 32 (2015), 2.9 WAR
Hayward, 8yr/$182M, 3.5 WAR the first two seasons
Lackey, 2yr/$32M at 36, 2.5 WAR, 0.4 WAR
Lester, 6yr/$150M (2015), 8.4 WAR first two years, 0.3 WAR in 2017
Montero, 3yr/$40M (2015), 1.8 WAR in 2015, -0.2 WAR next two years
Zobrist, 4yr/$56M at 35, 3.9 WAR in 2016, 0.2 WAR in 2017
Zobrist, Lester, Lackey paid off in 2016 but not overall, what got them the WS were some good trades (Arrieta, Chapman) and the farm, Bryant, Rizzo, Russell, as well as low cost FAs, Fowler, Hammel.