Since Bonds' return (not including today), the offense is scoring at about a 4.2 runs/game clip, which is slightly higher than their season clip of about 4.07 runs/game.
Small sample size, yes, but they only have about eight more games to evaluate this before season's end. The offense will obviously be better next season with Bonds, but:
- There's no guarantee he'll remain as good as he's been.
- There's no guarantee he won't miss significant portions of the season with injury and/or time off needed for rest.
- The starting rotation is competitive now, the offense is still poor now, so why assume to spend any extra money on the stronger portion of the team?
Something else to realize, too, is that 1st base isn't the only place on the team to upgrade. If the Giants realize not only the intense need to jettison Edgardo Alfonzo, but also the lack of need to keep Pedro Feliz, they can make trades to replace those two with a slugger. First base is the biggest need position to upgrade offensively, but 3rd base really isn't far behind.
UPDATE: Doesn't really prove my point, but it reinforces it a bit -- it's the 7th inning, in Coors Field, against an unremarkable pitcher in Sonny Kim, with Bonds in the lineup, and the Giants have yet to scratch the scoreboard. It happens to the best offenses, of course, but my point is that the Giants offense is not good, and isn't even adequate.
Of course, the Giants scored five runs in one inning last night, so I do suppose it's possible they could score six over two innings tonight. But let's just say I'm doubtful.