$150/month sounds a bit steep for this website in my opinion.
I know I mentioned to Trues in a PM, but thought I would post here in case he didn't get it for some reason (Got an error when I sent).
Anyways, how about moving to a web host that gives unlimited storage space and bandwidth, such as FatCow.com? Granted it's not eat all you want, but they say it should be enough to satisfy a personal or small/medium size business at $58/year. Probably more a pain than what it's worth though. (7zip'ing the files would help a bit as mentioned earlier)