We have $30M to spend just to get back to what we are spending this year, with more big contracts coming off soon. Money shouldn't be an issue here until you get to luxury tax levels, which we are NO where near.
The players you have to give up for Garza are not going to be spare parts, they are going to be pieces we'll actually need in the future. We aren't that well off that giving up the future for one or two seasons is going to pay off.
1) Yes, we are losing payroll but we also have arb raises and things like that, which will impact the payroll.
2) If you are paying 22+ million for Greinke and 16+ million for Jones plus other arb raises, how high is your payroll going to be? It doesn't matter if some deals are coming off, others will be added on. The payroll is going to have to be 130+ million, at least, to justify that.
3) And yes, you won't get him for spare parts but if you can get him for a package similar to what Chris said for Hamels, then I am ok with that.
If you are going to compete for a title, you're going to have to spend > $100m that's just how it works because you have to secure one wave of talent, and then have another cheap wave meet up with them at the same time to have enough depth to fill in a FA or two to compete.
You can't get hung up on those numbers, you are speculating right now, the market will bare what it will bare. You would have guessed $20m a year for Jones a couple weeks ago, maybe they only end up around $17-18m, hard to say right now until teams go shopping.
I would much rather keep Schoop and Birdwell than gamble that a guy is going to extend with you for the same money you don't want to pay him in FA. If you're spending the same amount either way (this year or in 2) I'd like to do it without losing prospects.