[gdal-dev] error allocatint [sic] destination buffer

[Even Rouault]

The only idea I have is pretty obvious and I guess you'd already have it, you 
probably require more memory than available. The --config GDAL_CACHEMAX 
500 -wm 500 options require at least 1 GB. Otherwise it's a more subtle bug. 
Unfortunately it's not very practical to try to reproduce it as your input 
datasets are pretty big to download.

I've downloaded the first two files and observed that they are at the same 
resolution and projection so you could probably use gdal_merge.py instead