I don't think that is entirely true. I certainly agree that you need to build a home-grown core. A cheap, young core allows the purchase of FA-priced added talent, whether by trade (disadvantage: lose prospect talent), FA (disadvantage: pay more total $), or international over-25 (disadvantage: little supply, know less about how they will perform in MLB). A lot of $$/salary-cap space does indeed provide a way to shortcut a total rebuild -- once you have most of a core (and we do in our lineup, plus Nola and Eickhoff in the rotation) you can afford to add several expensive talents through overpays.
In fact, there is the danger of perpetual rebuild, if you don't use your $ to push yourself over the top and into contention. Guys like Herrera, Hernandez, and Galvis aren't going to be at peak much longer. Waith and that is 3 more members of the base you need to replace. You can churn short of .500 forever, if you don't spend, as the young guys joining the team simply replace the established guys sliding over the hill and you churn short of becoming a winning team, because you keep waiting until you are just one or two guys short of the playoffs and that time never comes.
Why does that time never come? Because we don't have enough top talent in our minors that we are ever going to see a one or two year surge of a handful of average first-division starters or better. If you map out likely ETAs for our minor leaguers and assess who looks to be an average first division starter or better, I just don't see a magic time in the near future.
Part of it is luck. We need to find our current equivalent of the kick over the hill provided by Werth and Victorino. It's good that we are claiming pitchers on waivers and giving them a trial. That's very smart and very low cost.
I do not see at all how starting to spend big this winter leads to a one-year peak and collapse. A top starting pitcher is likelier to be a significant contributor for three years than for one. Lee was, and he was older than the guys out there this winter. Even Halladay at 33 gave us two excellent years then a year like the one Hellickson just gave us.