> But people who don't use the right aggregators will not be able to read past 10 posts.
I do not think such aggregators exist, and you can just ignore people using software that do not comply to widespread conventions.
> And if everyone was using aggregators, I wouldn't have such a high bandwidth bill.
I don't understand this sentence. All RSS client software is called aggregator.
> But sites that can have an RSS feed necessarily need to deliver their content in a static form.
Not really. Many websites which are essentially blogs are transforming themselves into single-page web apps. My uni's websites included. Some do it for the $$$, some for reasons that I can not know (jumping the bandwagons with minds toggled off).
You can just set your blog software to truncate your feeds to a reasonable number w/o any worries. And I suggest you look at your logs, because some silly bots might be consuming your bandwith along with your normal traffic; there are some that like RSS feeds.