I'd like to be able to deliver around 50MB of static content, either in about 30 individual files up to 10MB or grouped into 3 compressed files, around 5k to 20k times a day. Ideally I'd like to put some sort of very basic security around providing the data to ensure that a request is from the expected source, but if tossing the security for a big reduction in price is possible then it's an option.

Does anyone have any suggestions other than what I've found:

Google AppEngine is $0.12/GB & I believe has a file size limit of 10MB so I'd have to break the data up a bit. So a rough calculation would seem to be that this would cost me about $30 to $120 a day.

Or I've seen something like what seems to be just public static content delivery with no type of logic capabilities like Usenet.nl at what I think calculates to about $0.025/GB which would cost me about $6 to $25 a day.

Any idea if I'm going about these calculations right & if there might be a better option for just static content on a decently high volume delivery? Again some basic security would be great but if cost is greatly reduced without it then I'm up for that.