spring to mind immediately...
How do you shoot down something that is already nosediving?
The iterative approach is pretty common: buy as much as you can afford and then buy more when you can justify it. In general you'll want as much bandwidth and as many channels as budget allows. You might also try renting first if you are looking at serious kit.
I lost my phone in a bar in Wisconsin and found it three months later in my bedroom in Vermont. I wish it had GPS, it could have told me where it had been.