Right, but if you go with a "budget" dedicated supplier of dedicated servers for cheap (probably based out of EU such as Hetzner/OVH) or out of the US (through someone who provides "unlimited" bandwidth), have everything through s3 as a backup incase the server has any issues, you will be able to save money.

25 meg downloads don't last very long, so the very worst is that your gigabit pipe gets caught for a bit - hell even a company like Linode does 2GB out for $160/m :).

S3 is very expensive for what you are doing, saying you don't need to own/run servers for things like a podcast is just pissing money into the wind.